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View Full Version : BUILD LOG: Here we go again . . . MK4



routercnc
30-12-2015, 04:57 PM
I've explored the limits of the current MK3 machine and it's time for an upgrade ! I want to cut aluminium more successfully with a better surface finish.

Here is the design so far, generally happy with it but tweaking minor things here and there:
16942

16947

Z axis
Box-Z design clamping the spindle all round. 15mm 4off profile rails and 8 carriages. Went for the single Z ballscrew in the end as couldn't get a twin ballscrew design to fit and give reasonable travel etc.
16943

This is how the spindle clamps, but still keeps the rails aligned:
16944


Y axis
Twin ballscrew driven with box surrounding Z axis. All joints overlapped such that pre-load can be set on rails before tightening. Has 20mm profile rails on 5mm epoxy.
16945

X axis
Twin beam gantry design using 60x100x5mm RHS steel sections. This sits on 16mm open bearings which are on 16mm simply supported rails. Cannot get finance approval for 1000mm profile rails so am re-using existing parts. I'm going to use 6 open bearings per side to get the most stiffness out of it. When the time comes there is only minimal work to adapt to profile rail.

16946

The gantry is driven by twin ballscrews, and I tried lots of layouts to get them syncronised before getting to this one. Still not 100% decided - this one has 5M HTD pulleys 31.8mm dia with 15mm wide belts. To get the link across means bolting 2 pulleys back to back. Also thinking about a single 25mm wide pulley with 9mm belts shared between the stepper and the link across (2 belts per pulley), but need to read up about 9mm vs 15mm belt strength etc.

The energy chains are split down each side. LH side is for spindle power cable, RH side is for stepper power, home/limits, auxillaries, and water cooling pipes. Now that the control box is 24V logic for limits, (homes still WIP), and all cables are shielded I'm hoping that running them together in the RH side will be OK.

Not decided on water cooling arrangement, got several options which I'll post when I finally decide. The current radiator & fan is quite bulky and 'sticks out' where ever I put it.

routercnc
30-12-2015, 07:17 PM
I've started making some of the parts for the MK4 machine. Thought I'd start with an easy and relatively quick one.
Here is the Z ballscrew lower bearing bracket. The standard bearing bracket is too large to fit in so I've made my own again. I'll re-use the ballscrew and bearing from the MK3 machine which is already turned down to 6mm shaft at the end allow a pretty small bearing to be used. Just needs a new housing to suit the new design:

Laying it out and machining the bearing pocket:
16954

Machining the profile leaving tabs to hold it:
16955

Cleaned it up and set up to cnc machine the M8 pilot holes (note that this is a drill press vice - a proper precision vice is on my wishlist !)
16956

Started the taps off in the drill press (just to get them straight):
16957

Then finished them off in the vice with the hand tap wrench:
Since I discovered these lovely spiral fluted taps there is no going back . . .
16958

Chamfered the thread entry with my favourite snail countersinks, then cleaned out the threads with a bolt:
16959

Done:
16960

More to follow . . .

routercnc
30-12-2015, 08:14 PM
Next part is the Z axis stepper motor bracket.

Laying it out:
16961

Machining the pocket - no adaptive toolpaths I'm afraid so about 1 hour to machine this:
16962

Then the slot for the motor shaft:
16963

Small pocket to clear the boss on the front of the stepper:
16965

Light skim to get a level surface:
16964

Outer profile cut:
16966
I had problems here as I had the tool stick when it was about 10mm into the part. It was on one of the curves (which I think increases the chip load a bit) and I had about 2 seconds to go from hearing the problem developing to the spindle stopping rotating. I cleared the tool and thought I'd got away with it but it had obviously missed some steps as there was a ridge in the part. I let it finish, going easier on the feedrate, then homed the machine and ran some new full depth toolpaths working up to about a 0.5mm offset inward. This made the outer surface 0.5mm smaller all round, but at least it was smooth again. For this part it did not matter so I was lucky.

Machining the bolt slots was pretty quick:
16967

Set it on end and machined the clearance holes for mounting (thought this might vibrate but it was fine):
16968

Skimmed the other side down to get the final 20mm thickness:
16970
16971

That will do !
16972
OK, so it was not 20.00 everywhere . . . !
16973

Counterbored to 9mm deep (DRO coming in handy here to get them to the same depth)
16974

Snail countersink to finish off (love these things, so much better than the star type which are a waste of time):
16975

Done. Worked out OK in the end:
16976

routercnc
30-12-2015, 09:35 PM
Next part is the Z ballnut bracket. All started well . . .

Laying it out
16980

Pilot holes for the threaded holes:
16981

Skim the surface to level it:
16982

Machine pocket to house ballnut:
(Toolpaths are fairly basic from Cut2D - gentle ramp into material, then a series of simple circles. No spiral option. But it gets the job done.)

https://youtu.be/LQdc-aWgtjA
16983

Profile machined most of the way through leaving a bit holding it in place:
16984

16985

All holes drilled to size, tapped, then on the very last hole backing the tap out - it snapped ! Aargh!
16986
Tap was 12mm into the part and bashing and picking was not working. Flatten the end off the centre punch so that was no good.

Got some Alum powder (about 3.50 off ebay for 2x100g) and mixed up a solution with hot water:
16987
Then dropped in the part, and you can see it bubble straight away (bottom right hole).
16988
After a day there were lots of black specs and a general browny dust settled onto the part (hole now top left).
16989

But even after a couple of days it had only eaten about 0.5mm groove in the top of the tap. At this rate it was going to take weeks.

I tried a masonary bit (3mm tungsten carbide tipped) on a very low speed in the pillar drill and this gnawed away at it for about 15 minutes. The drill kept trying to wander off into the aluminium at the sides, so I flipped the part over and put the drill bit into the hole hoping this would guide it. It made a sound like it wasn't enjoying it much but I pressed on. After another 15 minutes of drilling I got to within about 4mm of the surface, and then the drill broke and got stuck in the hole. Luckily I managed to get it out. I've since put the part back in the Alum solution. I think another go with a 3mm masonary bit will have drilled the last bit out, but I think the thread might be beyond use. I could probably live without that bolt and use the other 5 but it is annoying me now. I'll clean it out and see what to do. Could enlarge the hole then make a plug with a flange on it and press it in from the reverse side, then drill and tap into that. Probably tap it before pressing it in just in case !

Clive S
30-12-2015, 11:49 PM
After a day there were lots of black specs and a general browny dust settled onto the part (hole now top left).
http://www.mycncuk.com/attachment.php?attachmentid=16989&d=1451510462&thumb=1 (http://www.mycncuk.com/attachment.php?attachmentid=16989&d=1451510462)
I read something about this in an earlier post and I thought it said you had to keep it on a low light to keep it warm for it to work

komatias
31-12-2015, 12:10 AM
.... it on a low heat to keep it warm for it to work

Fixed.

Have you tried putting more alum powder in to see if your concentration is too low?

routercnc
31-12-2015, 09:03 AM
Hi Clive, Komatias,

I'd also read about constant heat but I don't have a hot plate and using the oven/hob was not allowed so I periodically drained some off and topped it up with water from the kettle. It was wrapped in insulating cloths to keep it warm for as long as possible.

I added about 100g of powder initially, and changed the whole lot for a new batch of 150g after a day or so. There was always some undissolved powder in the bottom even with lots of stirring which meant it was saturated at maximum concentration.

It was working, just slowly. I think a hot plate or keeping it fairly hot would give it more chance, I'll see what I can get hold of.

I don't know if drilling with the masonary bit would have taken 15 minutes without the Alum powder treatment or if several days in the Alum had softened it. I'm nearly through with the drill so when I'm next in the workshop I should break right through.

komatias
31-12-2015, 09:42 AM
Masonary bits are too blunt. You would also need to spin backwards to aid removal of the tap. I have used special carbide spade drills to remove taps. The only place in the Uk that has them is
http://www.drill-service.co.uk/Product.asp?Parent=020460060000&Tool=377
Seriously considering stocking some in 2016

routercnc
31-12-2015, 10:12 AM
Good to know thank you. I'd ordered a solid carbide 3mm drill a few day ago, but these look better still.

JAZZCNC
31-12-2015, 10:38 AM
Please Don't get me wrong on what I'm about to say has I'm not pulling down what you have designed, it looks and sure will work great. But This design seems an awful lot of work and complexity and extra cost for no major benifit over a fixed gantry design.!

By this I mean the wide Gantry and wasted space at each end mean it will have about the same foot print and give about the same cutting area of Fixed Gantry.
If used Fixed gantry design with lifting Y axis allowing none lifting Z axis meaning minimal Z axis extension, essentialy just tool length would have been much stronger and far simpler design IMO.

Like I say just an observation which for the sake of others thought I'd mention and not pulling down what you are building or doing. It's looking great sure will work great and i'm looking forward to seeing it come along.

routercnc
31-12-2015, 04:10 PM
Hi Dean,

Thank you for the comments. I understand where you are coming from and I agonised and developed this design over the last 6 months or so, including looking at fixed gantry ( I think you are referring to that blue framed fixed gantry on youtube ?). I looked at different parameters trading this and that and trying to work through all the options. I think this is version 14 !

In the end I'm pretty happy overall with this concept and think it will be pretty stiff. I also thought long and hard about the arrangement of bits to make sure slip planes were in the right direction so that bearings were not trapped and pre-loaded, and that it could actually be built in a particular order without leaving impossible joints to make.

I also wanted it to look as neat as possible so a bit of the design is for aesthetic reasons as much as anything (e.g. curved cover plates on Y axis, metal junction boxes where the energy chains end)

I'll keep you all posted, but this is probably a long build so you'll all have to wait to see if it is any good at the end. I intend to do a few simple cuts on the current machine at different feed, speed, DOC,etc and film them before it is decommissioned. Then do the same simple cuts when this one is complete to compare the finish, sound (when does resonance, chatter start kick in) plus measure the static stiffness.

routercnc
01-01-2016, 08:39 AM
These arrived recently as an early Christmas present. Another ballscrew for the Y axis, and another pair of 15mm rails and carriages for the Z axis. All the other mechanical and electrical bits will come from the MK3 machine.

I ordered from Fred at BST automation. I should mention how the ordering works for custom orders. Obviously they cannot list every part in every size to I asked for a quote on the lengths I needed. This was a bit less than the website price, which was nice. I was then asked to add various items to the basket which were 'similar' to the parts I wanted. During the checking out I had to add a note to say the actual lengths I wanted, and then wait at the payment stage for Fred to amend the price. I could then confirm the order.

It's a but of a concern that the order shows stock listed parts and lengths, and you have to take it on faith (and Fred's confirmation emails) that the parts you will receive are the ones you asked for.

But I didn't need to worry - everything was exactly the length I'd asked for. They arrived in a cardboard box, not wooden, but it was well packed out.
16998
17000

I immediately checked the ballscrew and it ran dead true to the eye (unlike the previous ones from other sellers which arrived bent). Bearings were a nice fit on the machined ends, and the end machining was nicely done.
16999
17003
17001

17002

Last job was not forgetting to confirm goods received on AliExpress, which then releases the payment to Fred. Note how this is different to ebay. Overall very pleased with my first order from Fred. Would recommend.

Jonathan
01-01-2016, 02:22 PM
Are the ballscrew end bearings any good? The cheap ones I've seen, admittedly >2 years ago, all seemed to be quite poorly made as they exhibited end float, unless you fiddle about adding shims or better bearings. Have they improved?

For you ballnut mounts, I hope your spindle is accurately trammed, else the the surface the ballnut flange mounts on may not be perpendicular to the base within sufficient tolerance.

Looking at your design, I'm fairly sure that the weakest point will be the Y-axis. You've compensated for the small bearing spacing causing racking by using two ballscrews, which is good, however the carriage can still twist about the X-axis when a force is applied parallel to Y, due to the vectical compliance of the 20mm rail bearings. Assuming you got medium pre-load bearings (I hope not zero), their vertical stiffness will be about 274N/um. The cutter is central, so if we assume the force is distributed equally upon the Y bearigs, but in opposite directions, you'll get twice that stiffness as the bearings act in pairs (I think), so 548N/um. Bearing spacing looks like 78mm and about 200mm to the tool tip from the bearings in the Z direction. This means that the deflection at the bearings is amplified at the tool tip by a factor of 200/78 = 2.56. The stiffness of the bearings is therefore effectively reduced by the same factor, so 548/2.56=206N/um. Hmm, too be fair that's a fair bit higher that the ballscrew stiffness (I estimate ~50N/um for the two in parallel) so maybe it wont be dominant.

EDIT: Just noticed that's you've put the ballscrews on the ends of the X and Y carriages, not at the center (of stiffness), so the stiffness will be a bit worse.

routercnc
01-01-2016, 09:02 PM
Hi Jonathan,

Bearings:
I've not opened the bearing packets yet, but I'm expecting to have to make up a shim like I did last time. I've been able to make them work on the current machine so am not too concerned.

Ballnut mounts:
The spindle is as true as I can get it - note I'm at the mercy of the flatness of the supported rail on X, and on the flatness of the extrusion for the Y rail. Based on things I've made from the MK3 machine I think it will be OK. If not there are ways and means . . .

Stiffness:
Double Y ballscrew design went in at the outset because of the reasons you mention - it cannot rack so you can push the bearings closer together. But you are right, and it bothered me for ages, that for loads in the Y direction, where it rotates around X, there is a moment between the cutting tool (reaction) and the ballscrew (input) which is resolved in the bearings. As they are close together this moment is higher, meaning more deflection.
Ways around this are to lower the ballscrew and reduce the moment - I tried between the box sections but this makes the gantry even wider fore/aft. I tried underneath, which is very good for forces, but it would get swarf on it and if it hit a clamp it would be nasty. So it went on top. The mori-seki is like that so that sealed it.


p.s. What did you mean here?
". . .Just noticed that's you've put the ballscrews on the ends of the X and Y carriages, not at the center (of stiffness), so the stiffness will be a bit worse. . . "

Jonathan
01-01-2016, 11:02 PM
Bearings: Ok, thanks for the info - I'll continue to give those a miss.
Mounts: Sounds reasonable.
Stiffness: Understood - I wouldn't say Mori-Seki doing something one way is any reason to copy, as the relevance of their reasoning is unknown. Also I'm not sure my calculation in the previous post is any good, as the bearings are close they probably can't reasonably be considered as points, plus I ignored the position of the ballnut.
P.S: See here (http://web.mit.edu/2.75/fundamentals/FUNdaMENTALs%20Book%20pdf/Precision%20Machine%20Design%20Error%20Budget.pdf) , from page 53.

routercnc
01-01-2016, 11:34 PM
Well that link is quite read. OK, I think I get what you are saying there. I did initially put all ballnuts in the middle of the axis, at the centre of stiffness. I hadn't though about it in the way the article suggests, it was just an intuitive start point, but the flange on the ballnut means they need alot more space which pushes everything apart.

So the X axis ballnuts are now on the 'front' of the gantry, whereas the article suggest they should be further back in the middle of the gantry. Problem is that they would hit the X bearings and make everything wider which knocks onto the frame and bed. I've only got so much space and I had wondered about an enclosure in the future so don't want to go past the edge of the table with any parts.

The Y axis ballnuts are also on the side plate of the Y axis, not in the middle of the bearings. Again the flange would push them higher in Z, and they needed much more material under the bearing mounts at each end of the ballnut to support them. It all looked too tall when I drew it.

To summarise I think what the article is saying is that because things will twist and rotate, you should put the ballnut in the centre of rotation (that is rotation of the structural parts caused by moments) so that the nut sees minimum binding loads etc. I think that is a good principle to aim for where ever possible, however I think in practice the machine I've drawn will see relatively small loads at the ballscrew due to this deflection causing a radial / binding load on the ballnut and I'm not too concerned.

JAZZCNC
01-01-2016, 11:40 PM
Are the ballscrew end bearings any good? The cheap ones I've seen, admittedly >2 years ago, all seemed to be quite poorly made as they exhibited end float, unless you fiddle about adding shims or better bearings. Have they improved?

Jonathan the ones I've been getting from Fred are excellent far far superior to those things from Chai in every way. Finish quality and operation, they don't need a thing doing to them. They come sealed in Bags and lubed up inside a box and are light years better.!

Jonathan
02-01-2016, 02:16 AM
Well that link is quite read.

Mm, it's good stuff.



I've only got so much space and I had wondered about an enclosure in the future so don't want to go past the edge of the table with any parts.

I wouldn't prioritize the enclosure over the stiffness of the machine. The 'sufficiently strong' machine in my sig. is currently enclosed with shower curtains and sitting in a paddling pool containing 240L of coolant, in my friend's living room of all places. It's as crazy as it sounds, but it does work!



To summarise I think what the article is saying is that because things will twist and rotate, you should put the ballnut in the centre of rotation (that is rotation of the structural parts caused by moments) so that the nut sees minimum binding loads etc.

I agree that the radial displacement effects on the ballnut will be minimal, but I was still thinking about stiffness - namely that the center of stiffness is (by definition) the point where when the ballscrew applies a force (which can easily exceed the cutting forces), no angular deflection will occur. Prizes for working out how big the effect would be...

Dean: thanks, noted. If I ever design a machine where their form is not a constraint, I'll consider using them.

routercnc
13-01-2016, 09:25 PM
As I feared the return to work after Christmas means workshop time has significantly reduced. For various reasons I've only been able to get about an hour in there.

But I have been able to get a few sessions on the CAD and this has meant I was able to go over some of the other designs and have one last go at unlocking some of the compromises. The net result is I've developed some of the other ideas and ended up with what I think is a much better design.

Old one for comparison:
17242

Here is the new version:
iso
17235
iso rear
17236
X axis
17237
Y axis
17238
Z axis
17239
Just X axis showing gantry, ballscrews, epoxy (orange), and custom ballscrew floating end as the ballscrews were not long enough to mount the standard floating end.
17240
X axis drive and belt tensioning arrangement
17243
Side View:
17244

The new features are:
Gantry beams smaller
They are now 80x40x5 RHS steel (down from 100x60x5). I'd put too much emphasis on huge sections, whereas with a double beam gantry I could afford to scale them down and still have plenty of stiffness in reserve over a single gantry.
Because they are smaller I was able to re-configure the X-bearings, bring them closer together, and give more travel in X. They are now only 274mm apart which is getting close to my current machine spacing. I was also able to get the X ballnuts at the centre of stiffness, rather than at the ends of the gantry.

Y rails are much lower
With the smaller gantry sections the Y rails are now lower and closer to the tool, as are the Y axis bearings, which all provides more stiffness

Ballscrews lower
As the gantry sections are narrower I was much happier putting the ballscrews on the front and rear faces as there was much less of a bracket required to join them back to the main Y axis, therefore stiffer.
These are now much lower in Z which also puts them much closer to the tool, which reduces the moments, which lowers the forces on the Y bearings and makes the machine stiffer.
I was also able to put the ballnut in the centre of stiffness, rather than on the outer edge of the Y axis. There might be a marginal gain here I really don't know, but it does look nicer.

Y axis bearings spacing
By re-designing the gantry end plates to free up some space I was able to make full use of the linear rail and spread the Y axis bearings out considerably more than before - without losing travel. This should significantly improve the stiffness due to moment inputs when cutting in the Y direction. When coupled with the lower ballscrews there should be a double win here.
In one of my earlier posts I suggested that double ballscrew on Y eliminates racking - whilst this is true for rotations about Z axis, it is not for rotations about the X axis. To eliminate these you could add another 2 ballscrews lower down, but that is not practical (!) so you do still need to space the Y bearings out even with double Y ballscrews. Rotations about the Y axis are dealt with by having the double gantry beams no worries there.

X drive
I've gone with something a bit different here which does not use tensioning idlers. The steppers are on plates which are slotted, and the steppers are also in slots. Between them I should be able to tension the short belt up to the ballscrew, and the syncronising belt across to the other stepper at the same time by pushing the motor off into one corner. Everything is 5 HTD with 15mm belts.

Cooling
I've decided that there are a couple of options to place the radiator, plus the option just to go for the 'big metal bucket' out of sight. So I'm going to build it and then just see which one takes my fancy. Sometimes you can CAD things too much and get tied up in the last details.


Luckily the new design retains the parts I'd already made so nothing lost. Thank you for the comments made so far, stirring up the doubts I had about some aspects, and making me revisit the previous designs. I think it is all the better for it.

Right, time to start CAMing up some of the parts ready for whenever the next workshop session is . . .

routercnc
24-01-2016, 09:11 PM
This lot arrived recently.

2off - RHS for the raised X axis sides - seems pretty square and reasonably straight
17337
17338
17339

2off - 80x40x4 RHS for the gantry beams

1off 30x5 flat bar to reinforce the gantry beams where the rails will sit
17340

2off ballnut mounting blocks (~9 each)
17341

And 4off 16mm open bearings to double up on the Y axis to make 4 per side (no photo)

Also, got a bit of time this week end to nearly finish the X axis motor mount / belt tensioning plate:

Laying it out:
17350

First pocket:
17344

More cutouts and slots:
17345

Holes spotted, top skimmed, and profile roughed and finished:
17346

Bought a new 6mm 2 flute 45deg helix (for aluminium) carbide from 'cncpoorboy' on ebay (for about 9) recently and just tried it out.
http://www.ebay.co.uk/itm/201435034715?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Very impressed with the finish:
17347


Some work on the drill press:
17348
17349

Need to skim one side and tap the M5 holes for the stepper, then its another one done.

In case you were wondering the slot will hold the head of 2off M8 bolts to stop them rotating whilst allowing it to slide in the slot. On the other side will be a spacer and a bearing guide to tension the belt.

routercnc
06-02-2016, 10:40 PM
Tiny bit of progress. X axis motor mount / belt tensioner plate finished.
17523

Here is a trial fit of an M8 bolt head in the slot (final part will use an M8 nut):
17524

Also started making one of the bits on the gantry. I snapped a cutter on final the 20mm pass ! Always the worst bit right at the bottom of a deep slot when the chips can't get out. It welded up and I didn't stop it in time.
17525

Luckily I had a spare so finished the cut. Setting up for the holes in the edges.
17526

Clive S
06-02-2016, 10:51 PM
Coming along nicely where did you get that vise?

routercnc
06-02-2016, 11:21 PM
Hi Clive
Thanks for the encouragement! If I multiplied time taken per piece by number of pieces to make I might get disheartened. So I'm trying not to think about it.
Vice was from Arceuro. It was about 35 and is surprisingly accurate (a DTI along the fixed jaw barely moves) and the base is fairly parallel to the jaw runner surface (therefore workpiece is fairly parallel to bed)
But after first use the thread got swarf on it which went into the nut and it is very hard to turn. I can't get it apart to clean it out so if you get one put a cover on the thread first. It's actually a drill press vice but is working ok for my gentle machining
To be honest I am going to replace it with a precision vice as one of the future jobs needs to be more accurate than this and I'm fed up trying to tighten the screw. Arceuro make some nice ones with ground surfaces all over and antilift jaws. They are also quite low in height which is good. if I buy one and like it I may get another as a pair of vices can be really useful

routercnc
13-03-2016, 05:15 PM
It's been a while since I last posted and I'll explain why in a moment. I've made a matching pair to the last part, with a bit of finishing off to do:

17915

Reason for the delay is that I've noticed for some time now that even mild cuts are often generating lots of chatter. I think it has been getting slowly worse, and feeling the Z axis around the rails and bearings there is some relative vibration between rail and bearing, especially at the top left bearing, when the chatter occurs.

Problem is that the chatter can quickly lead to welding, and with so many parts to make for the new machine it was time to check things out. For info I have been running these 15mm linear profile rails (classed as 15mm minature) for about 5 years on 3 successive machines, and that they were bought as used from 'fa-systems'.

I stripped the Z axis down and found significant fretting on the rail, especially around the top left bearing:
17916

Luckily I had a second set of 15mm rails (new) that I'd ordered for the Z axis on the new mk4 machine. However, the hole spacing was 5mm further apart on the bearing carriages. I ended up drilling another set of 4 holes rather than 2 extra holes because the holes would have been too close to the existing ones:
17917

I took the opportunity to drill some access holes in the outer plate so I could assemble the Z axis as a unit, and then bolt it on to the Y axis. It's easier to get everything lined up off the machine rather than trying to assemble it bit by bit on the machine:
17918

I then set the first rail off a side datum, and then clocked in the other rail:
17919179201792117922

Then assembled the Z axis onto the machine:
17923

I trial cut revealed a much improved machine. A 1mm DOC at 900mm/min 12,000rpm 6mm 2f carbide was fine with no chatter.
17924

So is there a moral to this story? Well my rails were used when I bought them so it's had to be sure but for the occasional poster on here who asks about rail size then I will always recommend 20mm over 15mm.

Back to the new machine. As originally drawn it had 4off 15mm rails around a box Z. Although these are used as 2 pairs loaded against each other I did not feel confident in continuing with 15mm rails all round. Luckily I had left space in the Y axis to upgrade rails or spindle size. So it was a simple matter to add pockets and fit in 20mm rails. I've ordered 20mm rails from Fred, and will use the new 15mm rails just as auxiliaries away from the spindle where the loads are lower.

routercnc
16-03-2016, 07:15 AM
Whilst cutting another new part I used 'feedhold' to stop the machine just to check something was not going to collide. Then I hit 'start' but instead of continuing on a +X direction to the end of the cut the machine moved in +Y. It was about 8mm into a profile cut so snapped the cutter.

Luckily this was in the scrap part of the material so no harm done. I changed the bit, homed, ran it all again. Later on in the same profile cut (in the -X direction this time) it was almost to the bottom when I pressed 'feedhold' again to check one of the clamps was not going to get machined through. When I hit 'start' is again went in the +Y direction. Luckily I had my hand over the e-stop but it still took a chunk out of the part!

I've never had this happen before and haven't changed anything in software, just the Z axis bearing change. Any ideas?

Clive S
16-03-2016, 07:57 AM
Did you by any chance stop it in a canned cycle I have a feeling that it happened to me once.:confusion:

routercnc
16-03-2016, 12:29 PM
Did you by any chance stop it in a canned cycle I have a feeling that it happened to me once.:confusion:

I don't think so - I'll check the g-code when I get home as I wrote down the line number I stopped it on. I seem to remember lots of X and Y positional commands so probably not in canned cycle? It was cutting out the outline profile to a part which was almost a rectangle.

The last feedhold problem was done on a pass which had tabs on it, but it was about 50mm away from having gone up, across, and down to create the tab and was going in a straight line to the corner. I was about 20mm from the corner going X- when I pressed feedhold. Upon starting it went Y+ as if it thought it had reached the corner.

Next time I'm in the workshop I'll do some air cuts on the same file to see if I pressed the feedhold twice or something . . .

routercnc
16-03-2016, 09:00 PM
OK, looking at the gcode where I had the 2 crashes (when 'starting' after a 'feedhold') and I can see there are several straight line moves (must be geometry nodes all along in a straight line from when I was creating and changing the CAD), followed by a G2 radius arc in both cases.

#1
I've read about problems with feedhold in arcs so always feedhold on a straight edge. But I was definitely on the straight bit about half way along the top edge when I pressed feedhold. About line 930. It was some way off getting to the G2 ARC at the corner. When I hit start the machine went up in +Y and snapped the tool clean off.

I've loaded the file onto my house PC (hence the DROs are all zero!) Here is the first one:
17956

#2
This time, on the same part, I was cutting along a straight edge at the bottom, -X direction, when I hit feedhold. It had just done line 1060. This time cycle start moved the machine in +Y. I hit e-stop straight away this time and recovered it. However, there was a gouge in the work piece (!). It's cosmetic but annoying none-the-less.

Looking at the gcode shows another set of linear moves, followed by a G2 arc radius at the corner:
17957

I'll go back to the CAD and see if there are repeat nodes in the geometry as a start, but I'm confused by this as I've used feedhold for years and not had this problem. Now twice on the same part!

I went to Mach3 website in case there was a later version - but it's still R3.0.43.066 I which is what I am running now.


EDIT:
OK, the reason for the repeat straight moves is that there are tabs on those sides. Vectric obviously adds those moves in on every pass, but only adds the Z up and over move when the required depth is met. However, I was nowhere near the depth to create the tabs (they are only 2mm high) so that might be a coincidence. So, still confused about what is going on . . .
17958


EDIT2 / side note:
I've had to do a few 'run from here' operations after hitting the e-stop recently. It is probably out of position as it could be mid-step so I've found you need to:
1. Raise the tool right out of the workpiece
2. Re-home the machine
3. Press 'run from here' on the line you e-stopped on
4. It will show you the required resume coordinates in a window. Before accepting these you should jog or MDI to the X and Y positions it shows. If you do not it will try to move straight to that location which could be through a clamp or the workpiece etc. if you are low. This has caught me out a couple of times!
5. Press OK and it will rapid down in Z to the position it got to when the e-stop was pressed
6. Start the spindle (or there is a check box if you use spindle control from Mach)
7. Hit cycle start

routercnc
27-03-2016, 08:54 PM
Some pictures of the matching 2nd upper end part - cleaned, drilled tapped and finished:
18038

Then onto the next set of parts. Bed cleaned down and a new 10mm plate ready to cut out 4off bracket plates:
18039

Small pockets cut and holes spotted in all 4 parts:
18040

First one cut out:
18041

Last one cut out:
18042

Opening up the light cnc spots with the same 6mm spot drill:
18045

First pair of them cleaned up, drilled out, counterbored:
18043
The counterbore in each part was a bit nerve racking as it is to take an M8 cap head slightly under flush. This means a depth of 8.1mm in a 10mm part, which leaves just 1.9mm left. Although I had my DRO set on the drill press you still drill them blind and need to trust in the gauge not to go all the way through! I guess I could have used the depth stop nuts as a backup.

Second pair straight off the machine ready for drilling:
18044

routercnc
04-04-2016, 10:44 PM
Finished the 2nd pair off, cleaned up, holes drilled etc.
18090

These are the corner pieces on the gantry-
18097

Not that exciting so I thought I'd also post another way I just tried out of tapping the threads in those parts (well starting them at least) which is much quicker. I started with one of these tapping chucks from RDG tools - designed to either replace the drill press chuck or for use in the tailstock of a lathe. It has a tommy bar and the chuck is free to rotate and slide inside the morse taper housing:

18091
Link below (they are also on e-bay)
http://www.rdgtools.co.uk/acatalog/2mt-Lathe-Drill-Tapping-Attachment-88025.html

Although you are supposed to tap out the existing chuck and replace it with this one I didn't want to keep swapping them over. I'd looked these over at a show so knew that the MT3 taper comes off the chuck leaving a 12mm straight rod - perfect :
18092

Because the 12mm rod was greased I put it inside a plastic bag (to stop the grease going onto the chuck jaws) and then put in lightly in the chuck - just enough to hold it but still allow it to rotate and slide up and down:
18093

Here it is well into tapping the M5 thread:
18096
This takes seconds to do and you can feel the bite / back off and reduce the risk of breaking the tap.

Note that the drill press is NOT powered - I'm using the tommy bar to rotate it manually.

This worked really well, was very quick, and created threads which were perpendicular to the face. I finished them off by putting the parts in a vice and using a cordless drill.

I think the plastic will not last long, it started has started to tear already, so one option is to make a metal adapter tube which is clamped in the drill press chuck at the top, and contains a long bored out 12.05mm dia or so hole in the bottom to hold the greased rod on the end of the tapping chuck. If the bore is a good fit and there is grease in there it should stop the chuck falling out when you raise the drill press.

To have something set up permanently I might even modify a cheap drill press/stand (the ones where you put a mains drill in) to house a long rod attached to the drill chuck - a bit like the Arc Euro ones but their's only goes to about 6mm or so tap size whereas this goes to 13mm.

Neale
05-04-2016, 09:15 AM
I cheated a couple of days ago when I needed to tap some M8 holes in a slab of Ecocast I had just drilled. I held the M8 spiral-point tap directly in the drill chuck, and took off the drive belt on the mill (Warco VMC with multi-speed belt drive so easy to do). I could then turn the drive pulley by hand. Light down pressure on downfeed handle, and this was enough to get a good thread started, finished by hand later. For small taps, I have lightly guided them in the chuck jaws and tightened a tap wrench on to the shank (not square) of the tap to turn them. Especially with these easily-driven spiral-point taps, this works ok to get a thread started. But I'll have to have a look at the RDG tap holder the next time I see them at an exhibition - thanks.

routercnc
05-04-2016, 07:15 PM
Hi Neale,

Yes, done something similar to that by slackening the motor / belt tension levers on the drill press. But even with the belt slack there is still quite alot of friction and it still tries to turn the motor.

To remove the belt on my Warco pillar drill completely takes a bit of time and involves a ladder, a screwdriver to open the lid, and releasing the motor bolts and is not very efficient. It's not much fun for long due to the effort of turning the chuck & motor.

The method above is quick to set up (just a quick adjustment on the chuck jaws) and is then very easy to turn.

One thing I will note is that the tap slipped occasionally, even though I tightened it as much as I could. I don't know if they do a keyed chuck version but that might be better. Maybe a bit of degrease on the inside of the chuck jaws would help. Next time I'll also try a tap handle on the round part of the tap shank as you did.

routercnc
11-04-2016, 09:48 PM
Bit more progress. One of the gantry end plates was cut out over the weekend:
18179

Tonight I drilled and tapped all the various holes. Couldn't resist a trial fit of a couple of the previous parts:
OUTER VIEW
18180
(Note the tabs on each end still need facing off. I'll wait for the other one to be machined then do them in the same session.)

INNER VIEW
18181

With the side plates offered up:
18182

18183

18184

Another reminder of what the end sections should look like . ..
18187


I used the tapping chuck again which made light work of the threads. Also discovered I was holding the tap wrong. I had been putting the tap right into the chuck and it gripped on the round shank - liable to slip. Looking at the 3 jaws of the chuck I noticed that it has ridges in the centre of each jaw. If you put the square part of the tap into the chuck these grip the 4 sides nicely, with 2 jaws on the flats and 1 jaw (with the ridge) on one of the chamfers of the square. Hard to describe but just put the square shank of the tap into the 3 jaw chuck and it will not rotate.

Nr1madman
12-04-2016, 08:10 AM
Wow!
This looks like a masterbuild!
I love it when its over complicated ;)

Fancy, funny and fantastic!

mekanik
12-04-2016, 09:35 AM
Very nice,
Looking forward to seeing this finished.
Mike

routercnc
08-05-2016, 03:57 PM
An update on the next bits on the list - the gantry lower bearing plates. I need to make 2 mirrored parts, here is the first one progressing -

Setting up and cutting some slots. These are to adjust one of a pair of ballnut brackets. I'm going to run 2 ballnuts pre-loaded against each other:
18410

The other holes have been spotted (to finish on the drill press) and the profile cut out. I tried something a little different to try and get the profile size as good as possible. As this sits on the X bearings I want this to be a datum part during the build. The rough profile cut was +1.0mm, then another rough cut at 0.2mm, and finally a finish cut at 0mm. You can see the finish in the photo which is excellent. I'll check with calipers how accurate the overall size came out.
18411

I've yet to drill out the holes on the top, and there are lots of holes required in the sides, but I thought I'd try a quick fit to make sure all was well. No bolts yet just propped together but looks good!
18412

Here is the start of the one for the other end. I had to line this one up using a DTI and get it very accurate to avoid hitting the holes in the donor plate I'm using. I've cut the slotted holes, next up will be spotting and profile:
18413

routercnc
08-05-2016, 06:44 PM
Also, I'd made a few design changes a while back but hadn't posted them so here they are.

1. Z axis
-Twin ballscrew instead of single
-Main body machined from solid
-Upgrade from 15mm miniature rails to 20mm Hiwin
18417

18416


2. Y axis
-Double ballnuts, one fixed ballnut housing and one floating housing to allow pre-load to be added
-Simpler bracing pieces
18418

3. X axis
-Double ballnuts, one fixed ballnut housing and one floating housing to allow pre-load to be added
18419

Davek0974
08-05-2016, 07:04 PM
Twin ballscrews on the Z :hororr: - should be able to punch the cutter through the work with the motor turned off !

:)

routercnc
08-05-2016, 07:35 PM
Cheers Dave !

It might do that yes, but it is still one stepper motor so it's not any more powerful than before. Reason for doing it is that it should help reduce vibration as both sides of the Z axis are held when machining, not just one side.

Davek0974
08-05-2016, 08:02 PM
Following with interest ;)

routercnc
15-05-2016, 10:22 PM
The first plate has now been drill and counterbored:
18460

The second one is cut out:
18461

Spotted and ready for drilling:
18454

The DRO I fitted to the pillar drill works really well for CBs. Although the depth is not critical, it looks nice if they are about the same height as each other. These are the CBs for the M6 bolts, drilled to a depth of 10mm as the thread needs to stick out to get good engagement:
18459

All the top holes are now finished. Then onto a light sanding with well used paper, then green scouring pad to remove the scratches and after about a minutes work they look quite nice:
18455

Another dry assembly fit:
18456

Next job is the tapped holes in the sides. I bought one of these precision vices a while back to hold the work on it's side:
18457

Mine is the second from the top - Precision Tool Vice Type 2 - 90mm wide

But I need to make some special clamps to fit into the groove. Here is some 10mm plate roughly marked out. I should get 4 clamps out of this strip. I'll put the usual stepped clamp triangles under the far end of each clamp initially, but may add a packer piece of the right height instead to make setting up quicker.
18458

routercnc
20-05-2016, 06:41 PM
Slight change of plan. I decided to use the 10mm plate to make a nice set of clamps to replace the quickly made scrappy ones. I've been using odd bits of aluminium plate that were supposed to be 'temporary' but ended up being used for ages.

There is no hard and fast rule for the dimensions but here was mine:
18484

Here are the 4 small clamps I made out of that 10mm plate:
18480
The came out pretty well.

Now I'm using those clamps to hold the workpiece for the precision vice clamps:
18481

Here is the drawing for them:
18485

Here is one roughed out as a trial:
18482

Looks like it will work OK:
18483

Just need a set of 4, then I can use the vice to machine the holes in the side of the plates.

Anyone else made their own clamps for machining, especially if they have any extra / time saving / novel features ?

njhussey
20-05-2016, 08:27 PM
Nice looking clamps! I'm about to change the way I cut the kits for eBay, instead of using masking tape to hold them down on the bed I'm going to cut out the 915mm x 102mm (by whatever depth the balsa is, 1.6 & 2.4mm) out of a piece of MDF and then using a cutter twice the diameter I normally use (2mm in this case) rout out 1mm deep the programming so that when I cut the wing ribs or fuselage sides I can send the cutter up to 1mm below the wood to ensure I cut all the way through. I'll be making holding clamps (sorry about all the waffle to lead up to the clamps I'm going to be making!!!) the same shape as single servo horns which I can swivel over the balsa to hold it...going to use some scrap 4mm Ali I've got lying around...hope that makes sense? :)

routercnc
21-05-2016, 12:36 PM
Hi Neil,

If you mean using a spoil board then I'd agree that is a better way and one that I use as well for balsa/liteply.

Lee Roberts
21-05-2016, 05:51 PM
Nice work on the clamps, always handy to have.


Anyone else made their own clamps for machining, especially if they have any extra / time saving / novel features ?

These always stick out in my mind:

http://www.mycncuk.com/threads/4420-Hold-down-clamps-what-do-you-use

Some solid blocks from the side may come in handy for you, seen in this video:

https://youtu.be/MF4SK3ZIXGw

.Me

routercnc
24-05-2016, 08:14 PM
OK, to conclude making the precision vice clamps.

Here is the first one set up against a backstop datum (a parallel), with the top surface flush with the jaw (using another parallel to get it level - not in photo). This is so I could batch machine the 4 parts without having to zero and set each one up:

18499

By chance the long clamps I'd just made fitted into the slots on the side of the vice so I could hold it down to make the proper parts. For info the slots in the vice are 10mm wide.

I profiled the counterbores rather than using the drill press:
18500

Then the clearance hole. I don't like drilling deep holes with an end mill as they can jam up, but because of the counterbore they were quite shallow and there was no problem:
18501

Because of the datum plate on the vice each one took moments to set up, then a few minutes on the counterbore and hole and job done. Cleaned up the holes and finished:
18502

Works well:
18503

OK, now back to the main project. I dialled in the fixed jaw of the vice:
18504

I needed to drill holes in the edge of the plate so I used the back face of the fixed jaw to clamp to:
18505

18506

Here is the backstop datum so the second plate would drop in without having to zero:
18507

Then I offered up the parts and the holes were in perfect alignment (lower 5 holes in the plate). All was going well and I was really beginning to like this new vice! :
18508

Then I noticed a problem. The outer plate is clearance for an M8, and the end plate I'd just drilled/milled should be M8 tapped which is dia6.8. Clearly they were the same size.
18509

I checked the CAM and realised I'd picked the outer dia for the M8 tapped hole, which is 8mm. The inner circle, then one I wanted, is 6.8mm. This is because originally they were CAMmed for drill holes (so it doesn't matter which circle you pick), but at the last minute I decided to mill with a 6mm carbide to 6.8mm to save drilling out. But I didn't change the geometry so they were milled to 8mm. Aargh!!

OK, what to do!! M10 x 1.5 takes an 8.5mm pilot so I've ordered M10 button head bolts and will tap to M10 instead of M8. My M10 tap was from a car boot sale and did not want to cut so I've ordered an M10 tap from the same place I bought the M8. It is a spiral fluted tap and the last one I bought from them cuts really well and is good quality.

So I need to wait before I can assemble the end plates.

The other problem I had today was going too deep with a 6mm spot drill which clogged it up and jammed, then snapped it off in the part ! My fault for pushing it too far. Now I need to get a carbide cutting removal tool as someone posted in my thread a while back when I broke a tap.

Lee Roberts
24-05-2016, 10:39 PM
Sorry to read about the problems, all part of the fun...I think? Lol

On a positive note, you've got this as the money shot though a:

http://uploads.tapatalk-cdn.com/20160524/63cfef37daa48d09178f675ad8cd4c17.jpg

They look nice and look to be doing the job just right too, nice job [emoji481]

.Me

routercnc
31-05-2016, 08:51 PM
Update time. It soaked up many hours to get back on track. After a lot of prodding with any pointy shaped tool I could find, plus a soak in WD40, I manage to lever the broken spot drill out of the hole. The edge of the hole was a bit damaged where I'd levered against it but at least the hole was clear.

After checking the main part of the hole was still in alignment I bored it out from the 6mm spot size to the 6.8mm pilot, then ran the M8 tap into it. I had to give it a generous countersink to tidy up the damaged surface then all was well again.
18532

I also managed to drill and tap out all the holes in the bottom of the outer edge from dia8 (should have been 6.8 for an M8!) to pilot 8.5 and then used my new M10 spiral flute tap. As per my recent M8 tap this is also a RotoGrip tap and is very sharp and cuts really well. This one was 11.03, which sounds a lot vs the cheap ones but I think it is worth it having used both.

Here is the ebay link:
http://www.ebay.co.uk/itm/291754642629?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
In case the link expires in the future here is the description:
HSS Ground Machine Tap Spiral Flute M10 x 1.5 Quality Made by Volkel. Germany
18531

The button head M10 cap heads had also arrived so I was able to trial fit those. All looking good:
18533

Next job was to cut the RHS steel beams to size. I was going to mark it out and use the thin grinding wheel on the grinder to cut it but after lots of deliberation decided it was time for a new tool. In the end I went for this one which is the 355mm rage2 saw. This is because it can cut up to 120mm x 120mm which should cover all needs. It has a nice soft start and just drops through the steel with ease. It is also pretty square out of the box - helped by just having a pivot and no slides etc.
18534

The first beam was cut out and offered up. Looks OK. It is about 0.5mm short of the 730mm length as drawn to make sure I could set the end pieces the exact distance apart.
18535
18536

Next I need to cut the 2nd beam to length then I'm thinking about the best way to set the ends the correct distance apart. Current thoughts are to maybe use the CNC machine to drill out the holes at each end in the side of the RHS beam, including a special hole for a hardened dowel locator pin at the far end. There would be a matching locator hole in the triangular brace side plate at the far end to push the dowel through. This should set the far end housing a set distance from the near end housing.

Another option, is to CNC machine 2 shallow pockets into a large sheet of plywood to take the 'footprint' of each end housing and set them the correct distance apart plus have them squared relative to each other. I could just use a tape measure and square but feel like an assembly jig / guide would be nice. Any other thoughts?

njhussey
01-06-2016, 04:09 PM
That's looking good now, coming along nicely! Sad I know....but I do like to see lots of shiny metal with lots of holes drilled in....note to self, must get out more :wink:

routercnc
03-06-2016, 08:12 PM
Second beam cut to length using the first beam as a guide:
18548

Decided to use the CNC machine to drill the holes. Here is one of the beams clamped down and being dialled in. Obviously the edge is not very straight but I wanted to get it fairly close:
18547

6 holes at each end drilled and then milled to 6.8mm, plus a 6mm dowel pin hole at the far end:
18549

Then onto the tapping to M8:
18550
Yes I know, ended up with holes a bit close to the edge - they were covered by another part in CAD and did not realised I put them so close to the edge. Will still work, but could have been better.

Then a trial fit. Note that only the front beam has holes in, and these are only in one side. Still lots to do on these bits. It all fits and aligns well but as I suspected would happen when the bolts are tightened it lifts/rotates one end of the gantry about 0.5mm from the flat plane. This is because the RHS is not perfectly flat along the lengths and so the ends are forced to align with the sides of the RHS.
18551

I intend to machine just enough on each edge of each face to get it all square. This could be just the outer 3-6mm or so as I'm hoping the raised bits are on the edge / corners so just knocking these back a bit will create surfaces which are in plane with each other and square. I think that when I tighten the bolts the membrane flat parts will pull up tight to these new surfaces on each edge and everything will be square again.
I don't want to machine to whole surface as this will make the part quite a bit smaller. We'll see how it goes and then I'll repeat on the other one. Maybe should have done this before the holes . . .
but until it was pulled up tight I didnt know how much it would move.

Anyway then I'll take off the triangular corner plate at the far end and machine in a matching dowel pin hole which will allow me to get the ends the right distance apart from each other.

Actually on this note I noticed that the 6mm end mill I used to drill the 6mm dowel pin hole in the RHS actually made a slightly larger hole. Putting a 6mm shank in there showed it to be a loose fit. I suspect the runout in the chinese spindle may be adding 0.05mm all round so 0.1mm larger diameter? If so I'll use a smaller end mill and interpolate the hole but creep up on the fit.

Clive S
03-06-2016, 11:49 PM
Looking very nice ad sturdy.:applouse:

This is how I got my beams sorted I welded 15mm plates on each end and then had them machined parallel and to length. I also had two faces of the box machined to get the box section true so that the front plate could be bolted to the beams true.

185521855318554

routercnc
04-06-2016, 07:45 PM
Cheers Clive, good method.

Had a go at sorting out the beams today. I set the front beam using the datums I'd left on the bed:
18555

I used some shims to take out the slight rocking on the underside and get a better clamp:
18556

I then started to skim the face of one of the beams taking off as little as possible. I'd hoped this would only need to remove the high spots but in the end I had to machine back the entire face to get back to a level surface everywhere. Probably had a slight twist in it.
18557

Looked good. Actually this is the first bit of steel I've machined on this CNC and I did get covered in tiny showers of swarf. As it is hot today I had a T-shirt on and they were very hot!

Anyway, then I offered it up to the gantry and as I tightened the bolts I watched for any movement - there was none. I tightened all of the bolts then tried to rock the assembly and unlike before it was solid, there was no rocking on the base plates which means success! Very happy and back on track. Hopefully the other beam is just as straightforward.

18558

18559

18560

Looks quite nice although the steel bits will all get painted.

Lee Roberts
05-06-2016, 12:49 AM
Looking good, good luck with the next beam!

.Me

routercnc
24-06-2016, 11:01 PM
Well I haven't moved onto the 2nd beam yet for 2 reasons. Firstly I've decided to do all the work on the first beam and make sure it is all going to work out. Secondly, although the outer face is now machined flat, I realised that the lower face is not flat enough. So I started by machining that square to the outer face (part is upside down):

18768

It now sits properly on the base plate and is square to the outer surface:
18769

I then flipped it over and spotted all the rail fixing holes in the top surface for the rail.

Next up was to add the reinforcement plate on the inside. I chopped 2 bits to length using the new Rage saw - really easy and quick:
18766

I used metal epoxy to glue the strip in having first sanded and de-greased both surfaces. I then knocked them both with my knuckle and the epoxied strip one doesn't ring like the other beam. Although I'd added this strip to give reinforcement and extra depth to the rail bolts it has also helped with the resonance. Might help with the cut finish a bit:

https://www.youtube.com/watch?v=Pu8ZtS9RypQ&feature=youtu.be

Then opened out the small spots made on the cnc machine and then drilled and tapped the rail mounting holes to M5:
18770
18771

I haven't machined this top surface yet as I will do it as a pair with the rear beam to get them exactly the same. Although they will have 5mm deep epoxy on top to mount the rails on, and therefore don't need to be machined, the 'MDF mould' I'm drawing to pour the epoxy into needs to sit on a very flat surface. I'll show more when I've finished the design of this mould part.

Then a trial fit and it sits squarely on the base plate too now:
18772

18773

There is another bolt to go inside on the lower face, plus 2 holes to drill in the inner vertical face to add another connecting block. Basically the RHS will be supported on all 4 sides so should be a pretty good joint when done. Then the end plate will go back on with the stepper mount in.

Finally, something I wondered about recently. All the spot drills I've bought and used have been 90 degrees. The twist drill is 118 degs so when it goes into the hole it contacts only a 2 points until it gets going which is a bit hard on the drill cutting edges. Centre drills are 60 degrees so same problem. I had a look specifically for 118 deg spot drills on ebay and they only came up on the american ebay site and there weren't that many. I didn't look for long so could be me but are the 118 deg spot drills not popular? Or are 90 deg spot drills designed to give good centering alignment on 118 deg drills?

routercnc
09-08-2016, 10:34 AM
Other jobs around the house mean slow progress in the build. I've managed to get the second beam machined.

18998

18999

Drilled and tapped the M5 holes. I bought this spiral fluted tap which has different colour bands for different materials. I thought I'd try this yellow one (for steel) and it works really well.
19000

I've sprayed them with a light dusting of zinc galvanising spray (screwfix) just to keep the rust off and make them look presentable. I've found this sticks well to metal and resists scratching. (Note Spitfire languishing in the background :apologetic:)
19001

19002

Next job is to put it all together, shimming if required, then set it aside. Then move onto making parts for the bed.

routercnc
02-09-2016, 09:21 PM
I've put off assembling the gantry parts for now and moved on to making the bed rail supports. Here is the basic bed structure and the parts I'm making now are the large RHS sections on top of the uprights (highlighted).
19124

First job is the chop the RHS down to the right length. The Rage saw cut through in about 30 seconds, with minimal effort and just a few sparks. The section is 100x60x5mm wall thickness steel so very impressed:
19123

19125

Light dusting of zinc spray to make the marking out/spot drills easier to see:
19126

Dialling it in as best I could - it bumped around a bit when jogging along the edge but I got it pretty much aligned. From memory I think it was within 0.3mm high to low spots.
19127

Then onto spotting all the holes. It is longer than the machine so I did 80% of them, then pushed the part back and zeroed off the last hole to finish it off. Bit fiddly but actually not too much work.
19128

Then onto the drill press to get to work on it:
19129

I had some M6 holes to tap so used a generic spiral fluted tap but it did not feel good. The effort was high and I could see it twisting. In aluminium it was fine, but this was not going well and the thought of it breaking was too much. So off to ebay to get another yellow ring (steel) tap from Europa tool. Tried it out and the effort was much lower. It made short work of the threading, so ~7 well spent I think.
19130

Next job was always going to be a bit tricky as one set of the M5 rail mounting holes was on the radius. I spotted them on the cnc and went very slowly to reduce deflection. But drilling them on the pillar drill was not working - the bit was clearly deflecting away.
19131

So I knocked up a drilling jig:
19132
The existing tapped holes help locate the fixture to drill out the holes on the radius. I drilled the holes in the fixture a very close fit to the bolt diameter so am using them a bit like dowel pins - thought about getting some shoulder bolts but didn't need to in the end. Just tried drilling one of the holes (with a cordless drill as a quick test) and it picks up the spot drill mark and works well. Will do them all properly on the pillar drill.
19133

19134

In case you were wondering there will be 5mm epoxy on top of the rails which will 'fill in' the radius to create a flat surface to mount the rail. For now they are supported 16mm rail, but I've done CAD checks for 20mm linear profile square rail and it will fit fine and just needs a simple interface plate to bolt it to the gantry. But at 1100mm they get expensive so I'm not buying them at this point.

Next up is some simple holes in the side (will do these the 'old way' scribe, centre punch, spot, drill . . . ) and then repeat the whole lot as a mirror image on the other one.

I've also cut up all the vertical supports which go between the rail and the bed:
19135
These need the holes drilling out to around 9.0mm to allow 120mm long M8 bolts to pass right through and into a nut / nut plate in the lower extrusion channel (not shown), bolting the RHS rail and the uprights to the bed in one go. I think this will be better than using lots of little L brackets.
19136

All for now . . .

routercnc
04-12-2016, 08:50 PM
The uprights have been drilled out to 9mm to allow the bolts to pass through, and the ends have been machined flat both end to give 100mm length. You will notice there are only 7 of them - one was cut slightly short so I need to cut another one.
19800

I've stopped work on the bed rails because tapping on the radiused edge of the RHS was proving to be a problem. The 5mm tap felt like it was going to break when it partly broke through the other side, basically cutting a thread only along one edge. I've got a plan B which is to machine the area out completely and weld in some threaded bosses. More to come on that one.

Back to the gantry. I've been making good use of my new lathe and made 2off ballscrew floating bearing holders. Here is a walk through starting with the drawing:
19785

The part was hidden in here somewhere, just needed to get it out:
19786

Turned the outer diameter to size, then drilled and tapped the M8 hole:
19787

Then turned the part around, but was not confident on parting off the waste so cheated and used a hacksaw (lathe not turning).
19788

Then onto the boring of the internal features:
19789

As mentioned in another thread I bought a pair of calipers to check the critical bore diameter - it needed to house a sliding fit bearing, so I had to get it close. These are ~OK, but the adjustment handle is a bit low quality.
19790

It seems to have a quick release slide facility - don't know if this is intentional or not? Maybe I'll replace it with a nice brass one now I have a lathe.
19791

Here are the finished parts:
19792

Bearing lightly pushed in a bit to check it will work OK:
19793

Onto the adjustable brackets which are made from 25mm thick stock. I had to remove the clamp on the chop saw to fit it. This cut through 90% of it:
19794
Then I turned it around and cut the last bit off:
19795
Took about 5 minutes taking it steady. Very impressed with this saw.

Onto the CNC machine:
19796

First one machined out:
19797

Here it is next to the bearing housing:
19798

Trial fit:
19799
19802

Last job is to counter bore and drill out the 4 mounting holes, then repeat on the second one. This screenshot is a bit out of date but the ballscrew mounts are on the far right of the gantry:
19801

routercnc
12-12-2016, 09:01 PM
I've finished the second bearing housing:
19976

Then onto machining the counterbores . . .
19977

. . . and making pilot holes
19978

They were finished off on the drill press:
19980

Trial fit:
19981

Then back to the bed rail supports. On the original CAD I'd forgotten to include the radius on the edge of the box section, meaning the threaded holes were on a corner. Drilling and tapping these turned out to be a bad idea so I needed a plan B. So I decided to machine out some pockets and insert some threaded bosses. Here are the bosses - took quite a long time to machine all 16, but they are done now:
19982

Then machining out the pockets:
19983
19986

Trial fit - a gentle sliding fit. They locate themselves, but I'll still knock up a little jig to hold them in place so they don't move when being welded
19984

19985

Still need to finished the other rail support in the same way, then off to a friends to be welded in.

Clive S
12-12-2016, 09:23 PM
Very nice indeed its a credit to you. Would you mind telling me where you got the vise from in pic 3 its is very neat.

JoeHarris
12-12-2016, 09:35 PM
Ahhh this thread stresses me out! It's all toooo nice! Keep it up though I want to see this beut finished!!


Sent from my iPhone using Tapatalk

routercnc
12-12-2016, 09:58 PM
Cheers guys thanks for the encouragement. The end seems along way off still. Vice is precision vice from ArcEuro trade. About 100 - really nice would recommend it. Can use as an angle plate to square up against parts as all sides are ground

routercnc
13-12-2016, 07:50 AM
Link to the vice:
http://www.arceurotrade.co.uk/Catalogue/Workholding/Machine-Vices/Precision-Tool-Vices-Type-2

130-040-02000, Precision Tool Vice Type 2 - 90mm wide

104.24 inc VAT

Tom J
26-12-2016, 09:55 PM
"Looking very nice ad sturdy.

This is how I got my beams sorted I welded 15mm plates on each end and then had them machined parallel and to length. I also had two faces of the box machined to get the box section true so that the front plate could be bolted to the beams true"


How did you do it Clive? Asking as this should be done in one operation/clamping - long piece.
Thanks

Tom J
26-12-2016, 11:17 PM
As I feared the return to work after Christmas means workshop time has significantly reduced. For various reasons I've only been able to get about an hour in there.

But I have been able to get a few sessions on the CAD and this has meant I was able to go over some of the other designs and have one last go at unlocking some of the compromises. The net result is I've developed some of the other ideas and ended up with what I think is a much better design.

Old one for comparison:
17242

Here is the new version:
iso
17235
iso rear
17236
X axis
17237
Y axis
17238
Z axis
17239
Just X axis showing gantry, ballscrews, epoxy (orange), and custom ballscrew floating end as the ballscrews were not long enough to mount the standard floating end.
17240
X axis drive and belt tensioning arrangement
17243
Side View:
17244

The new features are:
Gantry beams smaller
They are now 80x40x5 RHS steel (down from 100x60x5). I'd put too much emphasis on huge sections, whereas with a double beam gantry I could afford to scale them down and still have plenty of stiffness in reserve over a single gantry.
Because they are smaller I was able to re-configure the X-bearings, bring them closer together, and give more travel in X. They are now only 274mm apart which is getting close to my current machine spacing. I was also able to get the X ballnuts at the centre of stiffness, rather than at the ends of the gantry.

Y rails are much lower
With the smaller gantry sections the Y rails are now lower and closer to the tool, as are the Y axis bearings, which all provides more stiffness

Ballscrews lower
As the gantry sections are narrower I was much happier putting the ballscrews on the front and rear faces as there was much less of a bracket required to join them back to the main Y axis, therefore stiffer.
These are now much lower in Z which also puts them much closer to the tool, which reduces the moments, which lowers the forces on the Y bearings and makes the machine stiffer.
I was also able to put the ballnut in the centre of stiffness, rather than on the outer edge of the Y axis. There might be a marginal gain here I really don't know, but it does look nicer.

Y axis bearings spacing
By re-designing the gantry end plates to free up some space I was able to make full use of the linear rail and spread the Y axis bearings out considerably more than before - without losing travel. This should significantly improve the stiffness due to moment inputs when cutting in the Y direction. When coupled with the lower ballscrews there should be a double win here.
In one of my earlier posts I suggested that double ballscrew on Y eliminates racking - whilst this is true for rotations about Z axis, it is not for rotations about the X axis. To eliminate these you could add another 2 ballscrews lower down, but that is not practical (!) so you do still need to space the Y bearings out even with double Y ballscrews. Rotations about the Y axis are dealt with by having the double gantry beams no worries there.

X drive
I've gone with something a bit different here which does not use tensioning idlers. The steppers are on plates which are slotted, and the steppers are also in slots. Between them I should be able to tension the short belt up to the ballscrew, and the syncronising belt across to the other stepper at the same time by pushing the motor off into one corner. Everything is 5 HTD with 15mm belts.

Cooling
I've decided that there are a couple of options to place the radiator, plus the option just to go for the 'big metal bucket' out of sight. So I'm going to build it and then just see which one takes my fancy. Sometimes you can CAD things too much and get tied up in the last details.


Luckily the new design retains the parts I'd already made so nothing lost. Thank you for the comments made so far, stirring up the doubts I had about some aspects, and making me revisit the previous designs. I think it is all the better for it.

Right, time to start CAMing up some of the parts ready for whenever the next workshop session is . . .
200922009320094


Amazing project - can not wait till is finished
I had similar idea how to drive two ballscrews

Clive S
26-12-2016, 11:40 PM
"Looking very nice ad sturdy.

This is how I got my beams sorted I welded 15mm plates on each end and then had them machined parallel and to length. I also had two faces of the box machined to get the box section true so that the front plate could be bolted to the beams true"


How did you do it Clive? Asking as this should be done in one operation/clamping - long piece.
Thanks

They were done on a Hurco VMC clamped and machined in one operation ie front and top faces machined and both ends. But I had to take the two beams to a guy with a horizontal mill to get the holes in the ends drilled and tapped.

Then the front gantry plate was bolted to the machined faces of the 60x60x5 box.
It was the only way I could make sure that the gantry would be square and true.

The drilling at tapping cost me about 25 for the 16 holes.

Tom J
26-12-2016, 11:53 PM
They were done on a Hurco VMC clamped and machined in one operation ie front and top faces machined and both ends. But I had to take the two beams to a guy with a horizontal mill to get the holes in the ends drilled and tapped.

Then the front gantry plate was bolted to the machined faces of the 60x60x5 box.
It was the only way I could make sure that the gantry would be square and true.

The drilling at tapping cost me about 25 for the 16 holes.

Very good price Clive, where was it?
For profile up to 50mm I use lathe with independent jaws.
All the machine I have access to are limited with size (sort of big model engineering)

Clive S
27-12-2016, 10:08 AM
Very good price Clive, where was it?

It was done by local engineering firm as a job on the side by the boss in Stockport.

routercnc
28-12-2016, 09:06 AM
Thanks Tom. Yes, lots of ways to drive 2 ballscrews - that one would work as well.

Your little machine looks really good. Nicely built !

routercnc
03-01-2017, 08:48 PM
OK, more updates. To finish off the info on the bed rail supports, here is the little jig I made up to hold the bosses in place:
20182

Here it is in position:
20183

It uses 6mm shoulder bolts to give a good reference position and picks up off the inner tapped hole already there. This holds the boss in just the right place for welding. It's now ready for welding - just need to catch my friend with the welder in the next few days or so. This is bolt down the supported rail which obviously uses a pair of bolts on either side of the flange.
I've also taken the opportunity to spot out the holes for a profiled rail (i.e down the middle) to make a future upgrade much easier to do.


Next up are the end plates which hold the motor mounting plates. Starting with a nice skimmed off the sacrificial board:
20184

Then setting up:
20185
(note that I've scribbled down the X, Y, Z coord of the workoffset on the drawing - I always write them down in case of power failure)

I'm making a mirrored pair here. A few holes, and a large pocket in the middle of each one. You can drill and screw through the waste first, but and I'll talk you through my approach on the large cutout as it worked quite well as an alternative. This is all to avoid those terrible tool witness marks from tabs.

1) Use an inside profile with a 1mm offset (remaining stock on the side wall) WITH TABS.
20205

2) Then drill through the tabs with a cordless drill to remove the waste:
20187

3) Manually jog the machine to remove most of the tabs (not critical to get all of it)
20188

4) Clean up profile pass to remove the last 1mm. I do this in 2 stages as this is what works for my machine. 1st cleanup 3mm DOC, 0.9mm WOC, final cut full DOC, 0.1mm WOC.

Gives this surface finish:
20189

Then bolting down, removing clamps, and onto the profile cut:
20190

Same approach as above using a rough cut leaving 1mm stock, then semi-finish 3mm DOC, 0.9mm WOC, and finish full DOC, 0.1mm WOC. A stiffer/better machine might do the finish in one pass. I'm also limited to 6mm max cutter on ER11 collet. Good finish anyway:
20191

Mirror part cut the same way, then some holes tapped and surface cleaned up:
20192

The bearing end plates were done in the same way:
20193

Then onto the bearing holders:
20194

20195

They will be a light press fit:
20196

Second one made:
20197

Trial fit onto the bearing plates:
20198

This allows the ballscrew end bearing position to be fine tuned when setting up.
__________________

Moving away from the X axis and onto the Y axis - the belt tensioning system progresses. Turned some standoffs to hold the adjustable belt guide bearings:
20199

20200
______________________________

Looking ahead I need to turn down the end of one of the ballscrews. Made these 2 bits to hold it in the lathe. First is a protective collar to stop the jaws damaging the ballscrew:
20201

Made it by boring a hole into some round stock on the lathe.
Then machined a hex onto some round stock:
20202

Then used the hex to give 120 degree spacing to machine the 3 slots. Don't have a hex collet block which would have done the job!
20208

Then back to the lathe to part it off:
20203

Then to support the end of the ballscrew as it passed out of the headstock a spider/collar to fit inside the lathe spindle bore and hold the ballscrew. The ballnut is then 'tightened' up against it. Copied the whole idea off Youtube so should be OK!
20204

JoeHarris
03-01-2017, 10:45 PM
Maybe by mark 4 I'll be this good - v nice


Sent from my iPhone using Tapatalk

Chaz
03-01-2017, 11:57 PM
OK, more updates. To finish off the info on the bed rail supports, here is the little jig I made up to hold the bosses in place:
20182

Here it is in position:
20183

It uses 6mm shoulder bolts to give a good reference position and picks up off the inner tapped hole already there. This holds the boss in just the right place for welding. It's now ready for welding - just need to catch my friend with the welder in the next few days or so. This is bolt down the supported rail which obviously uses a pair of bolts on either side of the flange.
I've also taken the opportunity to spot out the holes for a profiled rail (i.e down the middle) to make a future upgrade much easier to do.


Next up are the end plates which hold the motor mounting plates. Starting with a nice skimmed off the sacrificial board:
20184

Then setting up:
20185
(note that I've scribbled down the X, Y, Z coord of the workoffset on the drawing - I always write them down in case of power failure)

I'm making a mirrored pair here. A few holes, and a large pocket in the middle of each one. You can drill and screw through the waste first, but and I'll talk you through my approach on the large cutout as it worked quite well as an alternative. This is all to avoid those terrible tool witness marks from tabs.

1) Use an inside profile with a 1mm offset (remaining stock on the side wall) WITH TABS.
20205

2) Then drill through the tabs with a cordless drill to remove the waste:
20187

3) Manually jog the machine to remove most of the tabs (not critical to get all of it)
20188

4) Clean up profile pass to remove the last 1mm. I do this in 2 stages as this is what works for my machine. 1st cleanup 3mm DOC, 0.9mm WOC, final cut full DOC, 0.1mm WOC.

Gives this surface finish:
20189

Then bolting down, removing clamps, and onto the profile cut:
20190

Same approach as above using a rough cut leaving 1mm stock, then semi-finish 3mm DOC, 0.9mm WOC, and finish full DOC, 0.1mm WOC. A stiffer/better machine might do the finish in one pass. I'm also limited to 6mm max cutter on ER11 collet. Good finish anyway:
20191

Mirror part cut the same way, then some holes tapped and surface cleaned up:
20192

The bearing end plates were done in the same way:
20193

Then onto the bearing holders:
20194

20195

They will be a light press fit:
20196

Second one made:
20197

Trial fit onto the bearing plates:
20198

This allows the ballscrew end bearing position to be fine tuned when setting up.
__________________

Moving away from the X axis and onto the Y axis - the belt tensioning system progresses. Turned some standoffs to hold the adjustable belt guide bearings:
20199

20200
______________________________

Looking ahead I need to turn down the end of one of the ballscrews. Made these 2 bits to hold it in the lathe. First is a protective collar to stop the jaws damaging the ballscrew:
20201

Made it by boring a hole into some round stock on the lathe.
Then machined a hex onto some round stock:
20202

Then used the hex to give 120 degree spacing to machine the 3 slots. Don't have a hex collet block which would have done the job!
20208

Then back to the lathe to part it off:
20203

Then to support the end of the ballscrew as it passed out of the headstock a spider/collar to fit inside the lathe spindle bore and hold the ballscrew. The ballnut is then 'tightened' up against it. Copied the whole idea off Youtube so should be OK!
20204

Very awesome, loving the work you are doing.

JAZZCNC
04-01-2017, 08:17 AM
Coming along nice mate keep it rolling.:encouragement:

Davek0974
04-01-2017, 10:24 AM
Some quality surface finishes there, nice :)

Clive S
04-01-2017, 10:32 AM
Very nice build log I follow it very carefully its a credit to you. You could also call it tips and tricks:thumsup:

routercnc
04-01-2017, 07:06 PM
Well, thank you all for the kind words of support. Means a lot, especially coming from the seasoned machinists on here.

I've re-read some of my latest posts and have realised that they paint a glowing picture where everything I do is perfect and works first time. This is misleading for the novices out there so I've decided to include things that went wrong for posts where there is something of interest. Readers have just as much to learn from things that work for me, as well as what not to do!

So here are some things that did not go so well / areas for improvement.

1. When making the bearing holder I'd broken my last good 6mm carbide the day before and a new one had not arrived. So I was stuck with an old blunt one. To give it a fighting chance at the pocket I chain cnc drilled out some of the material using a 3mm drill bit:
20218

But the carbide bit made a nasty noise and was not happy. I switched over to a 3mm carbide and carefully cut it out. You can see the evidence of the 6mm blunt carbide on the top surface:
20219

I had another look through my draws and found a single flute 6mm carbide which I've used for plastic. I cut the outer profile out with that one, plus all of the second part.

2. The 'second part' in the photo was actually the third part:
20222
The real second part went on the scrap pile. On the drawing I'd called for a 36mm bore to take the bearing. After the roughing cut (~1.0mm under) I offered up the bearing and it almost fitted. Scratched my head and measured the bearing and it was actually 35mm. Using Vectric 2D you cannot leave stock etc so the quickest fix was to frig the tool diameter (e.g. telling the software that dia is '8mm' whereas it is actually 6mm gives you 1.0mm stock). Rather than re-draw the part, CAM, etc. I did a quick calc and frigged the tool. Bearing dropped in the new bore with 0.5mm clearance all round. Useless! Thought about making a sleeve, but 1.5 hours later had a replacement made with the proper size bore.

3. The radius on some of the corners is exactly 3mm. This is bad practice with a 6mm bit as there is suddenly a large tool engagement which leaves a witness mark. Better to go with 3.1 or 3.2 if radius is cosmetic. Look at the bottom right inner radius to see the slight chatter. Not a big deal, but one to be aware of.
20221

4. Vectric cut 2D does not have lead in/out. This means there is a tool witness mark at the start / end of the finishing cut. You can help with a ramp in, but the exit goes straight up past the side of the work leaving a groove/scratch. Look at the wall near the top left screw:
20220

Let me know if the bad stuff is as interesting as the good stuff and I'll include that too . . .

njhussey
04-01-2017, 07:19 PM
It's all interesting!!!....good to see the good as well as the bad...if you want to see ugly ill show some of my stuff 😁

Sent from my HUAWEI VNS-L31 using Tapatalk

AndyGuid
05-01-2017, 12:24 AM
It's all interesting!!!....good to see the good as well as the bad...

Ditto!
And this novice (little old me) finds your posts very easy and a real pleasure to follow.
Many Thanks, routercnc!

routercnc
14-01-2017, 06:54 PM
Brief update. Next up were the plates which hold those bearing holders . . .

Setting it out, drilling out some of the holes and pockets:
20360

Then bolting down through the holes so I can machine around the outside:
20361

Quick trial fit to make sure all is well:
20362

Went OK but broke a bit when I called for an 11 mm DOC instead of 1 mm in the CAM and didn't stop the machine in time.

I couldn't fit the standard ballscrew blocks in under the end of the gantry so am making my own. There will be 4 in total, 2 each side to allow me to pre-load one ballnut against the other to remove the 50 microns or so of ballscrew backlash. Here are 2 of the blocks, with 2 more on order:

20363

I need to machine 45 degree chamfers on the top of the block but don't have an Engineer's vee block
20364

So I machined up a jig with a 45 degree notch:
20365

Here it is in position to show the idea (tabs yet to be filed off):
20366

Then the blocks had to be squared up. There are lots of videos and info on how to do this on the internet so I won't repeat in detail. Great example here:
https://www.youtube.com/watch?v=tW8HNAlUXxU

In the photo below you can see a raw block (right) and the squared up block in the jaws (left). The brass rod is used whenever an un-machined face is against the clamping jaw otherwise it won't sit flat against the fixed jaw. The deadblow hammer is to make sure the part is seated in the vice.
20367

Once squared up I set it up against a backstop (actually a parallel doubling up as a stop - must make something better !). It is now ready to have the details machined into the end such as the ballnut mounting holes. I can't machine the large clearance hole right through the centre because the part is 50 mm long. Even machining both sides its a bit too deep. So my plan is to bore a precise 20 diameter pocket in the end (say 10mm deep), then set it up on the 4-jaw, indicate on that bore to centre it, then bore it out.
20368

paulus.v
14-01-2017, 11:36 PM
Very nice build and documentation of the process. Thanks!



4. Vectric cut 2D does not have lead in/out. This means there is a tool witness mark at the start / end of the finishing cut. You can help with a ramp in, but the exit goes straight up past the side of the work leaving a groove/scratch. Look at the wall near the top left screw:


You could split the finishing contour line and add radii in CAD if you are a perfectionist :friendly_wink:

routercnc
15-01-2017, 08:57 AM
Very nice build and documentation of the process. Thanks!



You could split the finishing contour line and add radii in CAD if you are a perfectionist :friendly_wink:

Interesting thought Paulus. I see where you are coming from but would I end up with an open contour? I'll check it out but I think Cut2D only accepts closed contours. Longer term I'm transitioning to Fusion 360 where these more advanced options are standard practice.

AndyGuid
15-01-2017, 09:52 AM
Thanks routercnc for that stock-squaring video https://www.youtube.com/watch?v=tW8HNAlUXxU

How serendipitous that I found your link to the video almost totally by chance. Enjoyed the presenter's humour also.

routercnc
11-03-2017, 10:28 PM
Some overdue updates . . .

To finish off the machining of the ballnut blocks. Chamfered 2 of the edges:
21038

I swapped the 3 jaw over to the 4 jaw chuck and dialled it in using the bore I'd machined out on the CNC. Got it to within 0.05 mm, so pleased with that.
21039

Drilled it out using a range of twist drills up to 25 mm, then bored it out to size
21040

Three more to go:
21041

Then used the CNC to spot out the 6 ballnut holes, then drilled and tapped then on the drill press:
21042

Then onto the mounting holes on the underside. Again CNC spotting the holes, and then drilling and tapping the M8 holes on the drill press:
21043

Checked it with a spare ballscrew - fits OK:
21044
_________

Then onto the side support plates - spotting out all the holes:
21045

21046

Drilled out, counter bored, and tapped:
21047
__________

Next parts are the tram plates. These connect the Y axis box structure (which contains the Z axis), to the Y axis bearing plates and allow the Z axis to be aligned in multiple planes to tram in the spindle. The adjustment will be made with M10 cup end grub screws before the main bolts are then tightened. I'll put a screenshot of the updated design in the future post.
Cutting them out:
21048

Spotted, drilled, counter bored and tapped:
21049

Here they are trial fitted to the side support plates (which then sit on the bearing blocks).
21050
________

Then onto parts of the Y axis box structure. Started with some eco-cast from aluminium warehouse. Nice and flat and in good condition:
21051
21057

Marking out the holes with a 3mm drill bit:
21052

Then machined out the pockets which will take the 4off Z axis profile rails. I did a very fine finish pass with large overlap on the bottom of the pockets to get them as flat as possible. There is some adjustment when everything goes together but best to get it close as possible:
21054

Quick check:
21055

Cutout, drilled, counter bored, and tapped:
21056

routercnc
11-03-2017, 10:44 PM
Next parts were the triangular supports. No photos of these being machined as I wasn't happy with first one. As the design was just a simple triangle I used tabs to hold it in place. But these left the usual witness marks on one edge which didn't look very nice. I tried to sand them out but wasn't happy.
So I started again and added some internal cutouts to add a bit of style, but more importantly allowed me to hold the part in the middle while I machined all the perimeter away:
21058

Still needs holes drilled and tapped in the sides, but decided to do a trial fit. It connects the tram plates to the side support plates:
21059

21060

Davek0974
12-03-2017, 08:26 AM
A work of art, very nice :)

It's very satisfying when you have made a pile of bits and they just all fit together perfectly :)

Zeeflyboy
12-03-2017, 11:17 AM
Great thread - always really interesting to see how people go about making the parts rather than just seeing the finished product.

Super chunky looking parts there as well. I dunno what it is about a nicely machined chunky piece of alu but it's just damn tasty!

routercnc
12-03-2017, 07:34 PM
Managed to cut another one out this morning:
21070

Another trial fit showing both triangular supports:
21071

Just 2 more to go for the other side.

Here is the current design for the Y/Z axis. You can see the tram plates (small grey rectangular plates) I mentioned earlier which will allow me to tram the spindle relative to the larger green bearing plates underneath.
21072

Initially I will put the WC spindle in the main housing and drive it direct. It might stay this way depending on how much better it is than today.

But if not, the following pictures show the alternative full feature version. The parts will be made to accept either set up.

Main feature is a home made spindle (Tormach TTS drawbar style with R8 collets), driven by the WC spindle via a pulley with different ratios, plus the addition of powered drawbar.
21073

Here is a rear view of the pulley drive from the WC spindle, which is connected via a sliding frame to allow the belt to be tensioned:
21074

This view shows the Z axis with power draw bar. This will give a simple push button tool release. I don't have pneumatics in my workshop so this is electrically driven via a stepper, through a pulley reduction drive, and finally through a ballscrew. Quick calcs show this should have enough power/torque to overcome the pre-load on the belleville washers (part of the drawbar retainer) to release the tool. The whole PDB system floats on sliding bearings so that it squeezes the drawbar against the spindle shaft, rather than loading up the bearings.
21075

21076

Here is an underside picture showing the spindle which bolts in via the lower flange. It is also held in place with the clamps further up the main body, which are also used to hold the WC spindle in direct drive mode:
21077

Here is a cutaway view of the spindle showing housing, bearings, draw bar and collet system. At the top you can see the pulleys for the drive and the belleville washers which hold the tool in place by pulling up the R8 collet, which in turn squeezes the 3/4" shaft of the tool holder. Google Tormach TTS for more info.
21078
(The power drawbar assembly is not shown in this drawing)

Still some finessing to do (e.g. tube connecting AC bearings in nose to upper bearings not in correct alignment etc.), plus still have to convince myself that I am capable of machining the spindle in the correct steel (oversize by ~0.3mm), get it hardened, then grind the bearing journals and the R8 taper to all be parallel and aligned again as they will be distorted. I'll need to make a fixture for my lathe to hold a die grinder or some other idea.
This is the biggest part of the project, the most risky, and the main reason I may just stick with the direct drive set up. But the attraction of big torque boost, the ability to run larger cutters, and the quick tool change keeps me interested.

Ross77
12-03-2017, 09:20 PM
Very nice, look forward to seeing the spindle progress.

Boyan Silyavski
12-03-2017, 09:40 PM
Now thats the most out of the box z design i have seen recently. No shame in using 8x Hiwin bearing blocks and 4x rails plus a couple of motors apart from the Hf spindle. How would you align all that stuff in place? Each piece must be carefully machined to a tight tolerance.

Ok. I know that you will patiently make it. Obviously not your first machine :encouragement: 2 questions:

1. Wasn't it simpler and better using BT30 spindle and servo motor on a fixed gantry?

2. So much effort in all places but gantry will slide on round open cage bearings? No square supported ones? :cower:

Zeeflyboy
12-03-2017, 11:08 PM
Boyan - in the first post ;)




X axis
Twin beam gantry design using 60x100x5mm RHS steel sections. This sits on 16mm open bearings which are on 16mm simply supported rails. Cannot get finance approval for 1000mm profile rails so am re-using existing parts. I'm going to use 6 open bearings per side to get the most stiffness out of it. When the time comes there is only minimal work to adapt to profile rail.

routercnc
13-03-2017, 07:27 AM
Now thats the most out of the box z design i have seen recently. No shame in using 8x Hiwin bearing blocks and 4x rails plus a couple of motors apart from the Hf spindle. How would you align all that stuff in place? Each piece must be carefully machined to a tight tolerance.

Ok. I know that you will patiently make it. Obviously not your first machine :encouragement: 2 questions:

1. Wasn't it simpler and better using BT30 spindle and servo motor on a fixed gantry?

2. So much effort in all places but gantry will slide on round open cage bearings? No square supported ones? :cower:

Thanks Boyan. This is probably about version 5 of the Y/Z axis design with all sorts of combinations tried out, some with single Z ballscrew, some with pulley driven ER straight shafts, and other options. Eventually the desire to have the option of pulley driven spindle (for lower speed, higher torque), much larger cutting bits, and the ability to add a PDB drove me to this design.
I wanted to make the stiffest Z axis I could as it is all won or lost here. The 4 rails and 2 ballscrews is as stiff as it can be (in concept terms) so went with that. I thought a lot about the alignment of the bearings as you cannot just machine everything and bolt it together. The Y axis box structure has slip planes to allow it to be pre-loaded up to the bearings to squeeze them together. I'll let you know if this plan works !

1. I agree fixed gantry would be even stiffer, but I needed to maintain a very large cutting area for wooden panels. If it was just smaller metal parts then you are correct. So this requirement has forced a compromise. Fixed gantry would have a very large working footprint and I don't have that space.
I also looked at lots of spindles including buying off the shelf BT30 etc but they are very expensive with PBD. In the end I decided to allow fitment of direct drive WC spindle (the hole is 80mm diameter), with the option of making a spindle later.

2. As Zeeflyboy has pointed out this has already cost a lot to make, plus there is more cost to come (more Z axis rails, more aluminium plate, more steppers and drivers, pulley hardware etc.) so the ~200 profile rails on X will have to wait. Agree it is a weak point, and will also give some loss of accuracy. For now they will have multiple blocks per side, not the usual 2, to get the best out of them. But the rail supports which they run on has already been spot drilled ready for profile rail. A simple adapter plate to the gantry will then allow the upgrade.

Clive S
13-03-2017, 07:58 AM
Here is a cutaway view of the spindle showing housing, bearings, draw bar and collet system. At the top you can see the pulleys for the drive and the belleville washers which hold the tool in place by pulling up the R8 collet

I to am following this with interest. Have you decided on the size and number of the bellevilles? Also could you give more details on the drive arrangement for the PDB as I am making one for my mill but using an intensifier (small jack) to give a 7:1 advantage with 12 belleville washers. From a post on the Zone by SDM

routercnc
13-03-2017, 12:42 PM
I to am following this with interest. Have you decided on the size and number of the bellevilles? Also could you give more details on the drive arrangement for the PDB as I am making one for my mill but using an intensifier (small jack) to give a 7:1 advantage with 12 belleville washers. From a post on the Zone by SDM

Hi Clive,
I'm only 50/50 on making the spindle+PDB as it is quite a risky project, and could well end up just using the WC spindle as direct drive. But in terms of spec for the PDB system I've not finalised on all the details. It does seem quite hard to find definitive numbers on things like tool pre-load.

I'm away from my home PC at the moment, where all the data is, but from memory I'd put in the same number as the Tormach PDB kit shows (~6?) since I would be using the same R8 collet style. I've read that the load applied using the Tormach PDB kit is OK for general work but could be on the low side and an aggressive cut could pull it out of the taper, so I could need more. They don't want to share the spec details (understandable) for the bellevilles so no more data than this. I can add more than this without a problem.

I've downloaded a calculator to work out loads depending on series or parallel arrangements and also give the total travel until it bottoms out. This is where the tricky bit is to ensure the loads and travel all work out.
I had allowed for 10mm total travel of the drawbar to release the tool, of which 6mm is used to remove the pre-load off the taper, and the remaining 4mm is to push it out and hopefully release the tool.

The mechanical drive system needs a lot of force/torque, so the 7:1 jack you are thinking of is a good start. I currently have a geared down stepper driving a 1605 ballscrew. I did look at a 1204 screw to get more ratio but the axial forces are very high and I didn't want go that route in the end. Again from memory it needed at least 8 Nm to turn the ballscrew. That's all I have for now.

Clive S
14-03-2017, 09:58 AM
I've downloaded a calculator to work out loads depending on series or parallel arrangements and also give the total travel until it bottoms out. This is where the tricky bit is to ensure the loads and travel all work out.
I had allowed for 10mm total travel of the drawbar to release the tool, of which 6mm is used to remove the pre-load off the taper, and the remaining 4mm is to push it out and hopefully release the tool. Thanks for the info. From what I have read (and I am no engineer) a R8 collet requires a holding force of about 2400 lbs to be safe. I am using part No. D2315162 washers from Belleville Springs 2 in P and 6 in S this give a free stack height of 28.5mm and a flat height of 24mm. 75% deflection height is 25.13 mm with a load of 12337N.

The guy on the zone recons 0.5mm will release the collet after the pre-load has gone.
The setup requires about 180Kg on the jack to give me 1260kg

I would be interested in the link for the calculator

routercnc
14-03-2017, 12:52 PM
Thanks for the info. From what I have read (and I am no engineer) a R8 collet requires a holding force of about 2400 lbs to be safe. I am using part No. D2315162 washers from Belleville Springs 2 in P and 6 in S this give a free stack height of 28.5mm and a flat height of 24mm. 75% deflection height is 25.13 mm with a load of 12337N.

The guy on the zone recons 0.5mm will release the collet after the pre-load has gone.
The setup requires about 180Kg on the jack to give me 1260kg

I would be interested in the link for the calculator

Hi Clive,
I got the info together last night but no time to post out. Similar to your findings.

R8 needs 2500 lbf (11,000 N or 1,100 kgf) to hold it, maybe a bit more to be safe
Used calculator on this website:
http://www.meadinfo.org/2009/07/belleville-disc-spring-stack-design.html

Used washers (())(( to get 15,000 N when flat.

Release distance was about 0.3mm (between holding load and flat load).

Looked at data on this site:
http://www.leespring.co.uk/browse_catalog.asp?rbunitOfMeasure=Metric&springType=W&partnum=&UnitOfMeasure=metric&specsCriteria=&subType=&isMIL=&pageNumber=8
part 500-125-1125

This was a quick look, I think it could be refined.

routercnc
23-03-2017, 07:42 PM
Mini update -

Cut out the 3rd bracing piece:
21222

Final one under way:
21223

All 4 profile ops done:
21224

Then onto the side ops. I need to machine several side features starting with 2off 6.8 pilot holes (to later take an M8 thread). Bit nervous as I'm trialling fusion 360 for the first time as it can do these pilot holes as spiral bores. Done a few aircuts and all seems OK from a cutting point of view (apart from that G28 as mentioned in another post).

Here is the fixture:
21225

Luckily I had planned ahead (!?) and the first triangular brace I made with the poor surface finish could be used as a support. It will be sacrificial as one of the ops will cut into it.
The vertical angle is held by the precision vice, with a backstop at one end. The part just drops in and is then clamped. I was just about to hit cycle start and I was called away ! So it will have to wait . . . .

routercnc
08-05-2017, 07:42 PM
I've been busy with other projects but back on it again and ready for some updates. I've had to re-read the last few posts so see where I'd left off so apologies if I repeat something.
Last time I left you in suspense over the holes in the side of the bracing pieces. Here they are being machined:
21557

All 4 pieces machined:
21558

Two of the holes need to be M8 tapped, and one is a clearance + counterbore. Here is the counterbore being done.
21559

Bit nerve racking for 2 reasons. Firstly the pilot hole was machined blind on the other side, so I had to hope I'd got it all lined up so that the counterbore appeared in line with the hole. As you can see it was all OK:
21560

Secondly, part was a bit close to the chuck. I'd measured it and knew it would clear. Clearance is clearance as they say but still glad it went OK. . . .
21561

Then tapping the M8 holes on the bottom:
21563

All 4 parts done:
21562

_____________________________
Then back to the side panels. They needed holes on the sides which is always a bit more awkward. Got them dialled in:
21564
21565

Machined the holes and noticed that the top edge had a slight climb to it across the width with one edge 0.05 higher than the other. I guess this is reaching the limit of my current machine when cutting out a profile. So I took a very light skim to get it square again. This needs to be square to make the whole box square:
21566

Repeated for the other one, then placed them machined edge side down onto an assumed good reference surface (lathe cross slide) to get them level with each other and then clamped them together:
21567

Then machined the other edge, by taking a minute skim off, and then machined out the holes:
21568

Then tapped the M8 holes:
21569

Final dry fit of everything:
21570

More to follow . . .

routercnc
08-05-2017, 07:59 PM
The tram plates also needed holes in the side. Here was the set up:
21571

These holes needed to go all the way through the part, which is quite wide. The cnc machine can bore about 20mm into the hole, so the rest would need to be drilled out. But I didn't trust the drill not to wander so machined the bores on BOTH sides of the part using this fixture. Then drilled it out on the pillar drill from both sides until it met roughly in the middle. Guaranteed to get a straight hole !
21572

Then counter-bored to hide the cap head and cleaned up:
21573

_________________________________

Onto the Z stepper mounting plate, which will hold to the 2 stepper motors. First time using Fusion360 so a bit worried about how it would turn out (didn't need to worry as it turned out and have not looked back). Exported the part as an IGES file from my CAD programme and used F360 for the CAM. Very impressed with it. Here is the part to be machined:
21574

As you can see I was still using a profile method to cut it out (hangup of using Vectric Cut2D), but have since learnt much better methods.

Holes:
21575

Profile:
21576

Stepper holes drilled and tapped, and done:
21577

More to follow . . .

routercnc
09-05-2017, 07:48 AM
Next up was a little job I'd been putting off until I'd got to grips with F360. These are going to be inserts which fit inside the extrusion to connect the bed uprights. I'm sure there are many ways to make these parts but I decided to get some practice on adaptive tool paths. Here is the first of 16 parts:
21583

It all started with a large 8mm sheet:
21581

I then machined 2 edges so that the parts would be the right length:
21582

Then over to the chop saw to rough them out to width:
21584

21585

Next part tool a while - machining the 3rd edge on each part in turn:
21586

Not sure if this is good practice or not but the 4th edge I did in small batches:
21587

All to size . . .
21588

Then 6.8 mm holes machined (ready for M8 tap):
2158921590

Now onto the angled sides. I made a fixture to hold the parts which had 2 datums for alignment:
21591
21593
21592

The fixture was dropped into the vice each time and aligned in Y (fore/aft) by eye as this is not critical. It only needed to hold the blank in the correct X (left to right) and Z (up and down) position.

Then a 2D adaptive to rough it out. I had intended to do a cleanup but this doubled the machining time and the parts fitted fine with just the roughing:
21594

The adaptive took about 2.5 minutes which was not too bad. I've done 8 parts, 8 to go . . .

Clive S
09-05-2017, 08:03 AM
Nice work following with interest:congratulatory:

JoeHarris
09-05-2017, 08:40 AM
Lovely work as usual, well done!

Nr1madman
09-05-2017, 08:40 AM
It's mechanical porno!! ;)

routercnc
09-05-2017, 11:19 AM
Cheers guys. It's very satisfying when it all works so glad you are enjoying it too.
For anyone thinking about jumping to F360 then I'd say don't hesitate. Its a powerful bit of software and is daunting at first but start simple and go from there.

routercnc
15-05-2017, 07:31 AM
I managed to finish all 16 inserts, so another job done:
21624

All the Y and Z axis material has arrived from aluminium warehouse. All fine except they sent me 5" round instead of 5" square. This is to make the block which holds the spindle. Quick phone call and they sent me the 5" square for free and told me to keep the round:
21626

So onto the Y axis sides. Here is the CAM:
21625

Laying out the blank:
21627

Holes:
21628

Profiled:
21629

Holes tapped:
21630

Then the corners had to be filed square to take the stepper bracket:
21631

Edge holes drilled and tapped:
21632

The second one was made the same way but snapped a cutter with the adaptive being effectively too aggressive. Actually it was my fault as I did not align the blank quite right and so the cut was too wide as the stock was not where the software thought it was. Anyway, we got there.

Couldn't resist a dry assembly to check it all fits:
21633
21634

There will be a piece of bent sheet over the front and rear, so checking this will fit flush to the stepper bracket:
21635

Then onto the Z axis. Here are the raw stock parts:
21636

Top plate being set up:
21637
21638

All for now.

Nickhofen
15-05-2017, 02:57 PM
Wow nice work so far!!!

routercnc
23-05-2017, 08:44 PM
Thanks for all the kind comments.

Onto the top part of the Z axis. Main holes roughed out.
21750

You will notice that it is all offset to the right and the front. I made an error setting up the job and started to worry there would not be enough stock. In Vectric Cut2D the job always starts at 0,0. So you need to find the stock edge, go in say 5mm, and then zero out there. Then run the part which will give you a margin around the edge. In F360 I defined the stock in the software (which was 5mm larger than the part) and should have zeroed out on the edge of the stock. But instead I used my old method (by habit) and moved in 5mm then reset. The net effect was that the part was 10mm over to the right, and 10mm forward. Would it fit on?

This hole was supposed to be 5.5mm from the edge - looks like I might be lucky!
21751

Counterbores done and used to hold the part:
21752

Profile cut - ooh, just fits!
21753

Then I walked in the 2 holes for the linear bearings. This is in case I ever make the power draw bar spindle and holds the chrome rails which the PDB mechanism floats up and down on.
21754

When I was machining these holes I was removing 0.02 mm at a time (from the diameter). I noticed it was consistently taking away material from the half of the hole nearest me, and nothing off the other side. Now these are small distances, and within the 0.05 mm ballnut backlash so could be that, but I did lots of passes and spring passes one after the other and it always cut on the side nearest to me, as if it was progressing / loosing steps in Y- direction.

Here is the part trial fitted (on top of the sides which are still raw stock):
21755

You can see that this also has stripes where the roughing stepped down on each pass, even though I did a full depth finishing pass. I checked for play in the Y ballnut and ballscrew mounting bearing and all was well. I pushed and pulled the spindle and all seem OK (well, as stiff as it always was anyway). I'll keep an eye on it as the final few parts need total accuracy !

Zeeflyboy
23-05-2017, 09:28 PM
beautiful work, it's all looking so nice and chunky!

paulus.v
24-05-2017, 11:32 AM
You can see that this also has stripes where the roughing stepped down on each pass, even though I did a full depth finishing pass. I checked for play in the Y ballnut and ballscrew mounting bearing and all was well. I pushed and pulled the spindle and all seem OK (well, as stiff as it always was anyway). I'll keep an eye on it as the final few parts need total accuracy !

Isn't your softwood spoilboard the problem? Holding that chunk of metal with only four small woodscrews... Just a thought, I don't have experience with similar setups.

I'm following with interest your nice work!

routercnc
24-05-2017, 08:38 PM
Thanks Paulus,

All thoughts are welcome. I did wonder if it might move the part but after it was cut out I grabbed it and tried to pull it around on the spoil board but couldn't move it at all. It was pretty solid.
I've cut lots of parts out using this spoilboard method and not seen this result before.
Also before I started the profile cut out I marked around the perimeter with a pen, and the part had not moved relative to this outline.
For the bores I was also only taking 0.02 mm cuts which is very little tool pressure, just taking whispers of metal off, and yet it still seemed to be progressing in the -Y direction by a small fraction each time.

So at the moment I'm assuming this is a new electrical or mechanical problem that has developed. I've put this poor little machine through quite a workout considering it was meant for plywood and balsa wood, so anything is possible. Maybe it has finally figured out it is making it's successor . . .

I also thought about whether I was missing steps on change of direction, maybe somehow the step active high/low setting had changed? Next chance I get in the workshop I'll check that and I'll run some G-code moving the Y axis back and forth various distances and at various feedrates (without load), stopping back against a DTI, and see what happens. Then I'll take it from there, repeating with the spindle on (no load), then some edge cuts, etc. and see if it returns to DTI zero.

routercnc
24-05-2017, 09:09 PM
Time for one of the side jobs. The linear carriages are buried inside the Z axis box so there is no easy access for greasing them. So I designed some remote grease nipple parts, turned from some 10 mm brass bar. Here are some of the almost finished parts (4 off assemblies required, so 2 bits to go . . .plus threads need tidying . . .):
21764

First job was to check the thread size and pitch for these 20mm hiwin carriages - turns out they are M6x0.75 (M6 fine).
21758

So I ordered an M6x0.75 spiral fluted tap and an M6x0.75 die. Quick check to see that I got it right (using the nipples which came with it):
21759

I had some errors transfering the photos for much of the next steps (files were corrupt) so I'll have to skip a few. First part being turned:
21760
.
21761

Then screwed it tight into the carriage and scribed a line on the direction of the outlet tube, and a line perpendicular to that one. This is so the outlet tube points in the right direction (as you will see later), and so that I could align the centre in the vice (next op):
21762

Then I made a fixture which would hold the part and used the perpendicular line to get it in the centre. The outer dia of the fixture was tight against the end stop. This all put the part in the same repeatable position, so I can machine 4 off flats and holes:
21763

Here are the first 2 assemblies, tightened up and pointing the right way (phew!):
21765

Trial fit:
21766

View from the outside:
21767

I'm just in the process of tidying the threads (undercuts, slight taper on first few threads, etc.) so they insert fully home. I've also got to add 2 flats on the outside near the grease nipple so that can be installed/removed with an M8 spanner.

The 4 upper carriages will have this system, but the lower 4 will have the bolts in until they need to be greased then an access panel will be removed from the underside of the Z axis (which keeps out the swarf as it is near the spindle), then the bolt removed and a long straight nipple extension screwed into each carriage in turn. So I only need to make one adapter for the bottom ones and keep it somewhere safe. That's the plan anyway.

Neale
25-05-2017, 07:56 AM
I also thought about whether I was missing steps on change of direction, maybe somehow the step active high/low setting had changed? Next chance I get in the workshop I'll check that and I'll run some G-code moving the Y axis back and forth various distances and at various feedrates (without load), stopping back against a DTI, and see what happens. Then I'll take it from there, repeating with the spindle on (no load), then some edge cuts, etc. and see if it returns to DTI zero.
That was my first thought when I saw your post. I found the same problem on my current machine on the Z axis - didn't show up on simple profiling jobs but when I did some heavy-duty 3D carving, it rapidly showed up. It's probably only a single microstep per reversal so a bit of gcode that moves, say, 50 times in each direction and comes back to a dial gauge will show it up. The clue in my case was that the error was pretty consistently number of reverses times distance moved per microstep. At least it's a quick one to check and eliminate!

routercnc
28-05-2017, 08:40 PM
I managed to finish off the remote grease extensions. The threads were tied up so the grease nipples now sit flush on the end of the tubes:
21786

Then machined 2 flats (8mm AF) which were aligned to the flats on the grease nipple. This is to allow the tubes be inserted after the bearings are fitted, making it easy to fit/remove the Z axis - something which might happen quite a lot when setting the machine up:
21787

Here they are complete:
21788

The single straight one (left side) is to service the lower bearings and is fitted to each unit as required, then removed.

Then onto the Z axis. These are the large side pieces, each 30mm thick. I'm machining them as a pair to get whilst I get them to size. Outer dimensions on most edges are critical as they will hold a pair of Z axis rails and need to be parallel, true, and hold a tolerance on the dimension.

They are too wide to go on their side on the bed or vice, and too thick to sit flat on the bed, so had to set them up on the edge:
21789

Dialled them in roughly to avoid having to machine too much material away
21790

Tops machined flat - left a tiny bit next to the vice which I filed away by hand:
21792

As the parts were too thick to machine the ends, I marked a datum on the left end (+0.5mm longer than final dimension), and one on the right end.
21793

Then set up a parallel edge. This was so I could flip the parts over and rest the machined edge against this. Took a long time to set it all up and be sure it was good, but them machined the other side.
21794

I was pretty relieved to get to this point with both edges parallel and part to size (96 mm). However what I didn't know at this point was that this new top surface was actually on an angle and it was more like 95.7 mm (!) on the other side. Don't know if the fixture slipped during machining or what. But it is out by way too much for the linear rails.
I think my recovery plan will be to re-machine both parts to 95 mm (1.0mm underside) , and then use machine epoxy behind one set of bearing carriages to fill in the ~1.0mm gap. This might turn out to be a blessing in disguise as this will ensure perfect alignment.

Then onto drilling and tapping the holes. Not much to report here, standard stuff tapped to M5. But I did make this tap guide from a bit of aluminium round. The last part of the hole is tapped to M5, then there is a 6mm clearance. This guides the tap into the thread perfectly. Might make so more for other sizes:
21795
21796

I didn't get a picture of the last ops but I basically machined the ends to final size using the datums machined on an earlier op. I had to flip the part to do both sides.

Once I sort out the edge machining problem, there are some straightforward holes / counterbores to come, then I need to figure out how to machine some detailed features onto the ends. I think I will cut a hole in the table the machine sits on and poke most of it through into the draw space underneath.
The final op after that is to drill an 18mm clearance hole about 200mm long through the centre of the part (ballscrew sits inside). I think I'll do that on the lathe . . . bit more thought required.

Lee Roberts
31-05-2017, 04:20 PM
Looking great and coming along nicely!

routercnc
31-05-2017, 08:00 PM
Looking great and coming along nicely!

Cheers Lee.

If I get a chance I'll post up a more detailed set of measurements and photos of the long side parts I'm making. Having measured them on my 'surface plate' they are out by more than I thought so I've spent the last few days working out what to do, including starting them again.
They need to be accurately made because they take linear rails on both sides.

Current plan is to use the lathe to square up the parts. I've got a couple of fly cutters on order which will go in the chuck, then I need to make a raised platform which sits on the cross slide (toolpost removed) which will hold the work. I'll then feed they work by winding the crossslide past the chuck and square up the edge. I have a ground straight edge which will sit behind the other edge of the path so when it is flipped over the freshly machined edge will sit against it and mean that the second edge will be parallel to the first.
Only problem is that the cross slide had about 110mm travel and the edge is 310mm long so I will need to index it along the ground reference edge 3 times. Will this give an accurate long edge or will it give an edge with 3 facets? I will find out !

Anyone with a better idea as it won't start work on the raise platform until the weekend ?

routercnc
31-05-2017, 09:15 PM
OK here are the detailed measurements showing how far off 96mm width the parts were (!). I think they slipped / tipped in the fixture, which I couldn't tell as I couldn't see the ref surface they were sitting on during the machining.
21817
21818

They are out along the length, and across the width. Annoying but there we go.

Current plan is to machine them square again (but obviously they will be undersize for width). Here is a sketch of what I'm thinking of attempting on the lathe:
21819

I've bought some 5mm thick aluminium strips which I will superglue and bolt to one of the edges using countersunk cap screws, setting them well underflush. Then I'll machine the edge back to get the part 96mm wide, using the lathe again, and then remove all of the screws (except the ones at the far ends which will hold the strip on, along with the glue). I can then attach the rail. Should look like this if all goes well:
21820

If it doesn't work then the strip can come off and I'll try something else. Thought about epoxy levelling all 4 surfaces, which I think can be done if I start on a level surface and do it in the right order so they all end up parallel to each other.

Another option is to do both sides but use steel strips instead. Then get them ground in pairs on a surface grinder so they are parallel and flat to each other.

I knew this bit was going to be challenging, but it must be right otherwise it will bind or not track straight up and down.

routercnc
09-07-2017, 08:49 PM
Progress has been slow because this has turned out to be more involved than planned.

I started by making a raised platform for the lathe. This was to hold the part whilst I used a flycutter to trim and true up the long edges, ready to take the add-on strips. Here are the long T-nuts being made:

Started with the drawing and some stock:
22126

Machined to size:
22127

Finished:
22128

Trial fit in the cross slide, plus made up some simple spacer tubes:
22129

The top plate (a large offcut) was bolted and shimmed using shim stock on the spacer tubes until it was as flat as possible:
22130

22141

Then a straight edge was dialled in:
22131

Edge skimmed back:
22132

Glued and countersunk screws used to add the extra strip:
22133

Ready to try again, this time a different set up which shouldn't move!
22134

Skimmed it all down to 96 mm trying to get within 96.00 - 96.05 everywhere. I used the height gauge to check progress and wrote the heights on the part. Here is it getting close.
22136

I also left a machined edge on one of the sides for the rail to align to.
22135

22137

22138

Hopefully that will be good enough for the rails to run on.

Machined the counterbored holes:
22139

Ready for the end features . . .

routercnc
09-07-2017, 10:14 PM
The part was too long for the machine so only one thing for it - cut a hole in the table:
22143

The profile pieces which make up the bed are not accurate enough to be used as a support. The sides are not flat and are not perfectly square to the bed (since that was skimmed by the machine). So I made up a 'tramming' plate:
22144

I bolted it at the bottom, then used a screw at the top to dial it in. Here you can see that before the screw starts to be tightened there is an uneven gap to the part I am machining (which is held at 90 degrees to the bed via the precision vice:
22145

Screw tightened until it made contact:
22146

I made up a strap clamp to hold the part and bolted it to the tram plate. Then it was ready to dial in by running the indicator up the side and adjusting until it was vertical:
22147

Then the features were machined:
22148

Took the part off and put it on the lathe, then used a centre drill (as a scribe) to mark along the edge (part not shown in photo):
22150

Then removed it and used the height gauge at 15mm (part is 30mm thick) to scribe a line. I was relieved to see it was exactly the same height as when on the lathe which meant they were both at the same point.
22151

Basically this meant I had got the lathe platform at exactly the right height, with the centre of the chuck in line with the centre of the part. The next op on the lathe is to drill an 18 mm clearance hole (for the ballscrew) about 190 mm deep into the part.

But that is on hold until I machine the end of the second part. Before I took the first part out I had added a backstop to pickup the edge. This meant it was in the right position. Here is the second part set up for the same end machining:
22149

Getting closer now but this bit is taking ages . . .!

Zeeflyboy
10-07-2017, 09:33 PM
Well you are certainly putting in the attention to detail - hopefully it pays off in the end with a nice and smooth machine.

Good to share your techniques too, always interested in how people approach certain problems or use equipment in creative ways.

routercnc
11-07-2017, 08:34 PM
Well you are certainly putting in the attention to detail - hopefully it pays off in the end with a nice and smooth machine.

Good to share your techniques too, always interested in how people approach certain problems or use equipment in creative ways.

Thanks Zeeflyboy. I hope it is smooth, especially the Z axis which needs to be accurate and aligned so that the 4 rails don't bind up.

Some more progress on the long side parts of the Z axis. I finished the end machining on the other side piece:
22190

Then it was over to the lathe to bore the 18mm clearance hole for the ballscrew to go inside. Here is the first one set up and a pilot hole being started at the bottom of the large counterbore:
22191

Worked my way up using larger drills and then removed the chuck and dropped in the final 18mm bit. This has a 2MT on the end so needed MT3-2 and MT4-3 adapters to fit in the MT4 headstock taper:
22192

This went OK but I ran out of travel on the carriage so needed to re-position the work closer to the headstock end. By doing this the 2 'tabs' on the end of the work (which were to stop it sliding under the pressure of the drilling) couldn't be used, so I ran without. I noticed after a while that the work had moved on me ! - so, I drilled and tapped some holes and mounted it directly to the plate, using the strap clamp I'd made earlier. This was much better. You'd think I'd have learnt by now that clamps can't hold work pieces and stop them sliding if the tool pressure is high.
22193

I had originally intended to bore from one end and make it a blind hole. But the drill was not long enough and although I could have bought a longer one I decided it was just as easy to drill from the other side and go right through. I'd just put a nice blanking cap on the bottom to stop the chips going up inside and landing on the ballscrew (it is right next to spindle where the chips will be flying around).

Problem with that was that the drill bit was not quite long enough and left a small ring of aluminium where the 2 holes met (the blank ring about half way down the hole):
22194

I managed the clean it out with my longest a round file and all was well. Repeated on the other part and big holes finished. I checked the ballscrews and they fit without touching the sides.

There is one small tapped hole to put in each of these parts, plus the blanking cap, and then they are done.

________

Spindle Block
Had a great surprise recently. The spindle mounting blank was too large to fit on my machine so I'd called in a favour from someone with a bridgeport sized / type CNC machine. I only asked him if he could machine it to size, then I would do the rest including somehow doing the 80mm bore in the middle. To my delight he gave me this back:
22195

22196

I couldn't have done that on my machine so I was very pleased to say the least! Now it still needs lots of M12 holes drilled and tapped in the side, some M8 in the front (for the clamps), and the bore is at 79 mm, so needs opening out to final size but that has really given me a head start on it.

The M8 and M12 holes are easy to do, just setting up time etc. The bore will need to be done by putting the part on the lathe cross slide and then I'll need to make up a line boring bar which will run between centres using a dog drive off a drive plate. I've seen this done but not done it myself so I might do a practice piece first.

Couldn't resist a quick dry fit just to check it was going to fit together:
22199

edit - just noticed the spindle block is upside down in the photo ! I'll make sure to turn it around before machining the mounting holes in the side.

routercnc
23-07-2017, 11:07 PM
There are a few jobs to do on the main spindle housing. Boring pilot holes on both sides of the block:
22255

Then the pilot holes for the M8 taps for the spindle clamp brackets. Spindle block is so big I had to get inventive on the fixture to machine these parts:
22257

Then onto the tapping 16 off M12 taps and 4 off M8 taps - took a while !
22256

Quick assembly check:
22258

Then noticed that some of the bolts were loose on the current machine. Wondered why it had been chattering more recently - was worried the small 15mm profile rails had worn, but then spotted this:
22272

So I had to dismantle the Y axis and tighten them up. 2 bolts had come right out, and one more was loose. The rail has also lost a bolt. I guess that is what happens if you ask a machine designed for wood to plough through endless 20 mm aluminium plate for months on end. Used loctite and tightened them back up. Also doesn't help that on 15 mm rail they use M3 bolts which are very small and you can't put much torque on the heads.

Then onto making the spindle clamps:
22260
22261
22262
22263
22264

Although I've got to bore out the spindle hole on the spindle block, I thought I'd check everything was going to fit together. Aligning first rail to master datum:
22266
(note the rails are slightly too long - have marked them up for gentle grinding back to length)

Dialing in the second rail, ref the first:
22268
22269

Then checking the vertical alignment showed that the 2nd rail was ~0.05-0.1 high towards one end. The large side plates they sit on will need the M12 bolts loosening and knocking round slightly when this goes together for real.
22271

Coming together:
22267

Then discovered a problem! The whole assembly is ~2 mm to big! The plate at the top of the photo should be flush with the side plate but is clearly too high.
22270

Bit of head scratching, and checking the drawings couldn't find anything I'd made which was out of spec. Then checked the profile rail and carriage and they were ~2 mm taller in total than the drawings I'd down loaded from Hiwin. I know it has been mentioned on this site many times but check the hardware before committing the drawing and making the other parts !
Luckily this is easy to resolve, just take ~2 mm off one the side pieces and everything will be back in line again. I'll leave that till later because everything has to be set up to get it all very parallel otherwise the rails will bind.

Onto making parts for the lathe to bore out the main spindle housing to final size . . . more to follow

Desertboy
24-07-2017, 07:22 AM
Damned fine work there!

Chaz
24-07-2017, 08:02 AM
Agreed, some of the best on this forum IMHO.

Nickhofen
24-07-2017, 08:59 AM
Very nice work.

Lee Roberts
24-07-2017, 09:58 AM
Looking great, I like the design for securing the spindle not seen it done like that before, I agree that your work is on par.

Look forward to seeing the lathe work, will you be video'iiinngg it as you machine it?

routercnc
24-07-2017, 12:36 PM
Looking great, I like the design for securing the spindle not seen it done like that before, I agree that your work is on par.

Look forward to seeing the lathe work, will you be video'iiinngg it as you machine it?

Thanks all, and thanks Lee. The clamps only hold the spindle to the back of bore, so it is not all round support, but should be good enough. As an upgrade if I make a new spindle this will mount via the lower flange to the base of the spindle block, which is arguably a bit stiffer. The tapped holes and counter bore area are already machined so it will just drop straight in.

I've not done fly/line boring before so am learning as I go. May video it, see how it goes. Will have a lot to think about to avoid crashing the lathe.

If fly/line boring is new to anyone I'll post a few pictures up soon to show how I'm going to approach it.

routercnc
24-07-2017, 09:48 PM
OK, so I need to bore this hole out to just over 80 mm to give a nice sliding fit on the WC spindle:
22292

To give you an idea what is required here is the finished fly-boring cutter mounted on the lathe. Chuck is removed, an MT4 dead centre put into the head stock end, an MT2 live centre (rotating on bearing) put in the tail stock end, and drive provided by a long bolt from the drive flange running through a lathe carrier (lathe dog). This may look precarious but it has been done like this for years:
22299

So here is the walk through to get to that point. First off I sketched it out:
22298

Then I needed a single point cutter so started with an old 10mm HSS cutter:
22296

Then marked the tool, roughed it out using an angle grinder with an inox blade. Then used the bench grinder to ground the required shape. Still a bit of finessing required:
22297

Marking out the tool carrying bar with 2 scribe lines - one in the middle (where the tool, clamp bolt, and adjust bolt will be), and one further down where the edge of the vice will be. This is to keep it aligned when machining the features:
22300

I needed to make a rotary alignment tool (don't have a rotary axis):
22301

Setup for first op:
22302
22303

Then used the alignment tool to rotate it 90 degrees:
22304
22305
Aligned to edge of vice jaw:
22306

rotated for 2nd op:
22307

rotated again for 3rd op:
22308

Over to the drill press for the dia 10 pilot to 40 mm depth:
22309

Then reamed (very slow, lots of oil):
22310

Holes tapped:
22311

Assembled and checking the fine tune screw was going to advance the tool in the range I needed:
22313
22312

Mounting between centres:
22314

Then onto the lathe carrier:
22315
22316
22317
22318
22319
22320
22321

The last part to make is a fixture to hold the spindle mount in place on the lathe cross slide. This will bolt down onto the T-slot nuts, and bolt up into the underside of the spindle block using the existing M12 tapped holes. The key feature is that it will have M5 grub screws at each corner to provide adjustment vertically (bore centre MUST be aligned to lathe centre height), and to provide adjustment in tilt in 2 directions. Essentially a tramming plate to get it all lined up. Here is the CAM:
22322
Flip side will be counter bored:
22323

Machining under way:
22324

Clive S
24-07-2017, 11:06 PM
OK, so I need to bore this hole out to just over 80 mm to give a nice sliding fit on the WC spindle:This is the guy to follow with lathe work this is part three but worth watching https://www.youtube.com/watch?v=mAzCVDF304o

routercnc
25-07-2017, 06:58 AM
This is the guy to follow with lathe work this is part three but worth watching https://www.youtube.com/watch?v=mAzCVDF304o

Thanks Clive. I know Keith's channel well, he does some great work.

For info he held the tool in the 3 jaw, which will have some run out, but as this is a single point tool it does not matter as such because it will still cut a circle. What it does mean though is measurements of the cutting bit (made with a mic or calipers between the tool tip and back of the bar) can only be judged relative to the last cut, not absolute. So if the cut needs another 0.25 mm taking off then that is the increment of the tool.
However, using between centres (effectively no run out) allows absolute measurements of tool stickout because it is revolving about the true centre of the bar, assuming the bar is straight. So if you want an 80 mm diameter cut you can set the tool to that distance before the cut. Of course you would still check the bore of the last cut as you proceed to be sure. Either way works.
Also I had to make a lathe carrier (to transmit the rotation) because couldn't find a commercial one that big (bar is 50 mm). I'm sure they exist, just didn't see one on a quick search and I made mine in the time it would take the postman to send one, plus it was 'free' from scrap material.

Lee Roberts
25-07-2017, 11:02 AM
Here is a video showing the same boring method in use :)


https://youtu.be/s8HM8ja9t-A?t=80

routercnc
31-07-2017, 07:43 PM
Cheers Lee, all good info.

Tiny update:
Drilled 3mm pilot holes ready to open up and tap to M5. These are peck drilled right through the 20 mm part using a 1 mm peck with full retract in between, and dab of oil each time the drill comes out of the part to clear the swarf. These take the leveling grub screws:
22424
22427

Then the part was flipped and the counter bores machined for the M12 cap heads:
22425

Then bolted down onto the top slide using the T-nuts I'd made for another fixture. The M12 bolts are a bit long so will need to cut them down. They will hold onto the side of the spindle block which already has M12 holes in it. There are some random threaded holes in the part but they were in the piece of scrap I made the part from:
22426

Zeeflyboy
01-08-2017, 10:43 AM
really interesting stuff... keep it up!

Nickhofen
02-08-2017, 10:28 AM
This cnc build porn must stop!
(Please keep it coming). :joyous:

routercnc
05-08-2017, 08:30 PM
Look forward to seeing the lathe work, will you be video'iiinngg it as you machine it?

OK, as requested here is a video of making a fixture, setting up, and then line boring the spindle housing . . .


https://www.youtube.com/watch?v=sYhDtuqzf2I

Still lots to do but another step closer.

routercnc
14-08-2017, 07:03 AM
I've decided to do another video, which takes much longer to put together so let me know if this is better than posting pictures.

In this video I attempt to align the 4 rails flat and parallel to each other. They still need lateral spacing/alignment but that will be the next step when it is assembled into the Y axis and they are trammed in. Here are the edited highlights:


https://youtu.be/QIVAXH1YjPs

Clive S
14-08-2017, 09:38 AM
Patience of a saint very nice vid:applause:

Desertboy
14-08-2017, 10:03 AM
I've decided to do another video, which takes much longer to put together so let me know if this is better than posting pictures.

In this video I attempt to align the 4 rails flat and parallel to each other. They still need lateral spacing/alignment but that will be the next step when it is assembled into the Y axis and they are trammed in. Here are the edited highlights:


https://youtu.be/QIVAXH1YjPs

It's always a joy to watch a true crasftmans at work

Zeeflyboy
14-08-2017, 08:11 PM
great work, with the level of attention you are paying to the details this is going to be a very impressive machine at the end!

routercnc
15-08-2017, 06:48 AM
Cheers for the encouragement Clive, Desertboy, Zeeflyboy.

Next up will be re-machining another 1 mm off the Y axis pockets to correct the small CAD error I mentioned earlier, then assembly/alignment of the Z and Y axis. Hopefully no more surprises!

Zeeflyboy
15-08-2017, 04:24 PM
there are always more surprises!

routercnc
26-08-2017, 10:38 AM
More progress on the Z axis.

Finishing touches, lateral rail alignment, and fitting the ballscrew.


https://youtu.be/yJBE-fxVh8Y

Clive S
26-08-2017, 12:11 PM
Beautiful, very nice big credit:thumsup:

routercnc
26-08-2017, 12:23 PM
Beautiful, very nice big credit:thumsup:

Thanks Clive. Y axis is starting to come together, will be next up in episode 4.

Nickhofen
26-08-2017, 01:05 PM
It is remarkable the persistence to detail, this is going to be a very good machine!
I like the drone capture camera also!:beer:

Davek0974
26-08-2017, 01:27 PM
It's a work of art!

Four rails on the Z axis :surprise:

Desertboy
26-08-2017, 02:16 PM
Thanks Clive. Y axis is starting to come together, will be next up in episode 4.

As every one know episode 4 & 5 are the best ;)

Nr1madman
26-08-2017, 04:50 PM
Its so beautiful that it hurts my eyes ;)

Zeeflyboy
26-08-2017, 10:47 PM
really really nice, and I love the editing too :)

routercnc
27-08-2017, 07:45 AM
Thanks everyone. More to come soon.

routercnc
04-09-2017, 09:42 AM
OK, here is Episode 4, building the Y axis. It ended up being longer than I originally planned so this is part 1.


https://www.youtube.com/watch?v=J5EjnAWrwGE

Nickhofen
04-09-2017, 01:20 PM
Awesome!!!

Desertboy
04-09-2017, 01:51 PM
OK, here is Episode 4, building the Y axis.


https://www.youtube.com/watch?v=-bzWSJG93P8
The force is strong with this one ;)

routercnc
04-09-2017, 03:25 PM
The force is strong with this one ;)

Cheers Desertboy - hope it is strong with this one !

Thanks for the encouragement Nickhofen and Mekanik.

Clive S
04-09-2017, 03:36 PM
As always an art form. May I ask did you make the grease nipple extenders if not do you have a link for them tnx.

paulus.v
04-09-2017, 03:50 PM
As always an art form. May I ask did you make the grease nipple extenders if not do you have a link for them tnx.

at post #109 (http://www.mycncuk.com/threads/9369-Here-we-go-again-MK4?p=91451#post91451)

routercnc
04-09-2017, 04:07 PM
Hi Clive,

Thanks for the kind words. I made the grease nipple extenders from a bit of brass. See post #109 in this thread. The top blocks have the right angle in, and there are 4 off. The bottom one is straight and there is only one - it is used for each of the lower bearing blocks in turn and then the block is capped off with a small bolt. You can buy straight ones, but couldn't find an angled one the right size.

The valves are M6x0.75 fine thread, very cheap off ebay. Watch out, some M6 grease nipples are M6x1.0 (ballscrew nuts I think are this size.)

My angled ones needed to be indexed so that the horizontal part would be in the right place when the vertical part was tight. Lots of ways to do it but I tightened the vertical part and then marked the radial exit location.

...
Sorry got distracted part way through typing the reply, Paulus beat me to it.

Clive S
04-09-2017, 04:22 PM
You can buy straight ones, but couldn't find an angled one the right size.

The valves are M6x0.75 fine thread, very cheap off ebay. Watch out, some M6 grease nipples are M6x1.0 (ballscrew nuts I think are this size.)
Yes you are correct re the ball screw size M6x1.0 also worth noting is that if you unscrew the pip (nipple bit) out of the body that is also the same thread. In than case (although you might have done it already) if I could find a 90' nipple with the M6x0.75 thread it might be possible to take out the nipple bit and make a straight extension.:beer:

Zeeflyboy
04-09-2017, 07:03 PM
could watch those videos all day long....

Great work as always

MartinS
04-09-2017, 10:31 PM
Brilliant, your videos are almost as good as the build!

They say so much of your standards, is the rest of your life so disciplined or don't you have time!?

-Martin

routercnc
05-09-2017, 11:05 AM
Brilliant, your videos are almost as good as the build!

They say so much of your standards, is the rest of your life so disciplined or don't you have time!?

-Martin

Like most families life is hectic and unpredictable. Making stuff is stress relief and is fitted in when I have time. When anything is published it looks relaxed and flowing but reality is lots is happening in between !

routercnc
09-09-2017, 04:32 PM
OK, episode 5 is now ready. This is part 2 - finishing off the Y axis build.


https://www.youtube.com/watch?v=pDT8MmO_a2s&feature=youtu.be

Clive S
09-09-2017, 04:47 PM
You are putting us all to shame. First Class

Zeeflyboy
09-09-2017, 05:42 PM
Just awesome... no other words.

Desertboy
09-09-2017, 06:29 PM
Utterly stunning, your putting machining shops to shame there.

routercnc
09-09-2017, 07:11 PM
Wow, thank you guys. It's really encouraging.
@ Clive - Not trying to put anyone to shame! Just hope it inspires others to keep going on their own machines and designs.
@ Zeeflyboy - thank you.
@ Desertboy - thank you too. Much slower than a machine shop though, would never make money at this rate !

njhussey
10-09-2017, 10:32 AM
Fantastic build and craftsmanship, really enjoying this build. It's going to be one hell of a machine!

Sent from my HUAWEI VNS-L31 using Tapatalk

Nickhofen
10-09-2017, 11:53 AM
Top notch build!!! Thanks for taking the time to make all those videos also!

Desertboy
10-09-2017, 06:07 PM
@ Desertboy - thank you too. Much slower than a machine shop though, would never make money at this rate !

My Grandad used to say good workmanship is priceless, that's why I'm not paying lol ;)

routercnc
10-09-2017, 08:41 PM
Thanks again guys, keeps me going.

@Nickhofen - You've got Lee to thank/blame for the video series after he asked if I could video the line boring operation on the spindle block. I managed to get a bit of footage and patch it all together, and actually quite enjoyed the process. But I was using Windows Movie Maker, which is good to get you going (and free), but it only does the basics.

So I had a search around and found Adobe Premier Elements (release 15). This does the lot (as far as a novice film maker could see !), multiple channels, multiple audio, picture in picture, green screen keying, special effects, etc. It was about 90 on a disc, which I was hesitant about, but then found a downloadable version for 47. I can thoroughly recommend it, and have made the rest of the videos using that. There is a bit of a learning curve but they guide you through it and you soon get going.

For a 10 minute video on YouTube it is taking me (all together, excluding the actual filming) 5 to 10 hours of editing, which includes trying to get the right music to suit, timing the videos to fit in with the audio or vice versa, editing the clips into small pieces to prevent long boring or repetitive sections, playing with the format to keep it interesting, and selecting the best bits from several takes.

You also have to think while you are machining or building what shots to take and what it is going to look like in the end. To help this before filming I've usually done a few storyboard sketches to get an outline of what I'm about to do, but this can change a bit depending on how the section of build goes as I'm trying to guess what may happen.

Once I'm happy with it there is about 30-40 minutes of rendering/exporting, which creates an mp4 file, then about 30 minutes of uploading to YouTube, then about 10 minutes of admin on the titles/text including adding the copyright information for any music used.

So, in short, I'm glad you are enjoying it because if not it would be back to this thread with a few photos and a bit of text !

mekanik
11-09-2017, 09:49 AM
This build has to be one of the best shown on the forum and i know all the guys really appreciate the time and effort you have put into your video links.
Regards
Mike

Zeeflyboy
11-09-2017, 09:54 PM
Don't you dare stop the videos, I love them!

Desertboy
12-09-2017, 07:47 AM
Don't you dare stop the videos, I love them!

Exactly if you stop the videos everyone will have to go back to watching normal porn instead, you know with 5 midgets spanking a man covered in thousand island dressing ;)

routercnc
12-09-2017, 05:31 PM
Message received ! Desertboy you have a strange mind !

Desertboy
12-09-2017, 05:40 PM
Message received ! Desertboy you have a strange mind !

You are not the first person to mention it lol but also I watch south park ;)

https://www.youtube.com/watch?v=CXu5ErnoXJ4&list=RDCXu5ErnoXJ4&t=7

To me south park is the funniest thing on tv ever if you exclude four candles of course lol ;)

https://www.youtube.com/watch?v=pV1IP4N9ajg

routercnc
23-09-2017, 12:45 PM
OK, episode 6 is now ready at last. This time we are building the main gantry parts . . . enjoy !


https://youtu.be/tijVFCKuLPc

Desertboy
23-09-2017, 01:03 PM
you're blurring the lines between art and manufacturing

Nickhofen
23-09-2017, 06:02 PM
Grate job!

Clive S
23-09-2017, 06:09 PM
Grate job!

Nick That means put it on the fire:joker:

Nickhofen
23-09-2017, 06:15 PM
Nick That means put it on the fire:joker:

The keyboard demon strike again,lol!!!
Great Job!!!

routercnc
23-09-2017, 06:17 PM
Could be because I used an old marble fire surround as a surface plate to build on?!

Zeeflyboy
23-09-2017, 06:22 PM
Awesome as always...

Just curious - clearly you are pilfering quite a few bits like screws from your current machine.... given that your current machine is clearly not half bad, wouldn't it make more sense to buy all new parts for the new machine, therefore keeping the old one operational and then selling it as a working machine on here?

Desertboy
23-09-2017, 07:38 PM
Grate job!

22867

routercnc
23-09-2017, 07:52 PM
Awesome as always...

Just curious - clearly you are pilfering quite a few bits like screws from your current machine.... given that your current machine is clearly not half bad, wouldn't it make more sense to buy all new parts for the new machine, therefore keeping the old one operational and then selling it as a working machine on here?

I had to read that a few times - thought by screws you meant fasteners (!). OK, ballscrews, right . . .

Good question and yes that was an option but there are several reasons:
It might not look like it but the current machine is actually on it's last legs in several areas. It is on a knife edge for aluminium and I have to keep the feeds low, intervening regularly. Things improved a year or so ago when I replaced the Z axis rails (15 mm miniature rails) as these had developed free-play. But it has started chattering again and I think that 15 mm miniature rails are just too weak. The linear bearings on one leg of the gantry has also developed free-play which is probably not helping. Because I know the machine I can work around these and keep it dialed in, but I'd feel bad handing this onto someone else, especially a beginner.

Before final de-commissioning I intend to make a video of various cuts at different F&S and depths etc., showing the maximum performance and all the noises it makes. Also measure the stiffness of the machine one last time. Then (some time later) repeat on the new machine, and hopeful see some improvement.

I also re-built the bed some time ago to make it much stiffer. The new machine support rails have been designed to drop straight onto the old bed so I would like to re-use that and save making someone again. That much aluminium profile, especially the heavy gauge stuff that I have, is quite pricey.

So once the bed has been re-used, that only leaves the gantry (which I will re-use the 20 mm linear rails on as these seem OK) and the Z axis (for which the rails are earmarked for the sliding part of an ATC carousel as that is all they are good for). The various bits of plate will be used for future projects, including a few parts for the new machine once operational.

I have sold parts of earlier machines on ebay, but this time around I was happy to just migrate the good bits across to the new one and keep this hobby ticking along.

Zeeflyboy
23-09-2017, 08:36 PM
That was a far more comprehensive reply than I was expecting - I thought I might get a "nah mate" lol.

Well certainly seems fair enough, Given what great results you are getting I never would have guessed your machine was marginal!

routercnc
24-09-2017, 08:20 AM
DOH! Just looked at the thumbnail for this video and noticed that the corner plate is held on with cap head screws - they should have been button head screws. I watched the video again and the other 3 corner plates are held on with button head screws. Hopefully no-one noticed :whistle:

routercnc
07-10-2017, 05:24 PM
Episode 7 now ready . . . . lots of small jobs


https://youtu.be/dKhR4bTSWHM

Davek0974
08-10-2017, 08:33 AM
Amazing, pure machinery porn.

The only thing I could add, based on the detail level in that axis is - where you have the grub screws for head tramming bearing upon the aluminium plate I might bore some recesses and let in some small steel pads, aluminium will give a little over time and your head could lose tram, especially when looking at the tolerances you are shooting for ;)

routercnc
08-10-2017, 08:59 AM
Amazing, pure machinery porn.

The only thing I could add, based on the detail level in that axis is - where you have the grub screws for head tramming bearing upon the aluminium plate I might bore some recesses and let in some small steel pads, aluminium will give a little over time and your head could lose tram, especially when looking at the tolerances you are shooting for ;)

Hi Dave

I think you are right and it will give over time. I had gone for big grub screws and lots of them to spread the load but aluminium is soft. I could do with washers without the holes - don't fancy turning them from stock. Anything you know of that's available?

Davek0974
08-10-2017, 09:24 AM
Don't know anything off the shelf, might just need some 10mm rod and part some 4-5mm discs off.

Clive S
08-10-2017, 10:08 AM
I like the approach to make the pre-load in the screws with two nuts.:applouse:

routercnc
08-10-2017, 11:36 AM
Dave,
OK, will have a look at what I could do there.

Clive,
Cheers, I don't know if this is going to work but it's worth a shot to see what happens. I'm only going to fit them to the Y axis to see how it goes. I have some spare nuts to do the X axis as well.

I have some belleville washers on order in case the spring washers don't work out. It will really come down to how much speed I loose on the steppers due to the extra load causing them to stall out earlier.