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Joe's 1000x600x200 steel and aluminium router started
This will be the 4th machine I've built but the first for 10 years and the first I have posted a thread on. After various house moves, workshop rebuilds, etc, I am actually without a functioning router for the first time in ages which is extremely frustrating!
This machine will be reasonably compact, work volume of around 1000x600x200mm. It is very similar to the first router build by Boyan, in that it has a self supporting bed frame with raised X rail supports. I need to process aluminium, carbon, modelling board and maybe hardwood.
Frame is 80x80x3 welded steel box.
Gantry is 160x80 extrusion (Item series 8 heavy or clone thereof).
Plates will be 16mm cast milled tooling plate which I will have to produce on my manual mill.
Ballscrews from Fred, 1610 on X+Y, 1605 on Z, with BK/BF12 AC support blocks.
Hiwin 20 on X and 15 on Y+Z. X rails will be epoxy levelled with West 105/209.
I'm going to use steppers (in the past I used DMMTech servos) but seemingly 3N steppers with digital drives are quite suitable for this small machine.
I have done the basic dimensioning so I can get started on the frame. The gantry plates and Z axis will be adjusted as required but the sketches below should give you (and me) and idea of where I am heading.
Attachment 26759
Attachment 26760
Attachment 26761
Frame box section cut to a fairly good tolerance on the trusty/rusty Rage2.
Attachment 26762
And frame welded up, not quite finished yet, needs some end plates and reinforcements to catch the screw supports and motor mounts. I used an inverter stick welder, quite a revelation, amazing capability in something the size of a lunch box. Was quite careful to avoid warping, not by limiting heat but rather by carefully sequencing the welds to counter each other. I can't measure any warpage so it was successful.
Attachment 26763
I would would welcome any input on the basic design, but more urgently I'd like some help on the following:
1. Where is the best place to buy cast milled plate from? The guy I last bought from locally has gone to the wall.
2. What is the minimum constant temperature you would risk an epoxy pour with 105/209?
3. Has anyone bought extrusion from Alprofil? http://www.alprofil.com/aluminium_profile_frames.htm
Cheers, Joe
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Re: Joe's 1000x600x200 steel and aluminium router started
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Re: Joe's 1000x600x200 steel and aluminium router started
Thanks Andy, will call KJN tomorrow, they don't list the price for 160x80 on their site.
Last time I used a 6"x2"x0.25" aluminium box section, it worked ok but wasn't particularly flat or straight. I'm hoping I can use the slotted profile gantry without having to shim the rail. Milling the gantry is a pain as my mill only has 700mm of travel so would need to move an re-reference and would loose accuracy.
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Re: Joe's 1000x600x200 steel and aluminium router started
Looking good, classic design. Ballnut brackets off gantry plates may need a bit of support?
I’ve always ordered from aluminium warehouse as you can select the exact size you need. Other members have mentioned cheaper sources elsewhere (Smiths?).
I tried to keep 21deg C for the epoxy pour but from my brief experience with it I wouldn’t be concerned going down to say 18. I guess the heat might be required more at the beginning to keep the viscosity lower for the self levelling as it should generate its own heat as it cures. Others may have more to add on that.
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Re: Joe's 1000x600x200 steel and aluminium router started
I've only used Aluminium warehouse for tubes in the past, couldn't complain about them, product came well packaged, but I've read on this forum their cast plate is sometimes delivered damaged? I guess the plate you received was ok?
I've reconfigured the gantry end plates and extended the gantry. I wanted to keep the nut holder fixing on the outside so that I can fit simple angle over the screw to keep debris off it. With this configuration I would recess the X bearing plate and the gantry extrusion into the gantry end plate a couple of mm to keep the gantry vertical to the X rails.It also provides enough space outside the X rail to bolt up through the X bearing plate into the extrusion.
The (red) ball nut holder assembly will be adjustable up and down and if I make the gantry a few mm wider it will allow me to shim the ball screw supports off the steel frame to get the screws properly aligned, making the absolute length of the gantry beam non-critical.On my last machine I didn't have enough adjustment to align the X ball screws properly and it was a bit of headache to sort.
Attachment 26768
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Re: Joe's 1000x600x200 steel and aluminium router started
Made some more progress, capped box sections ends:
Attachment 26796Attachment 26797
I'm now waiting on the ballscrews to get here (next week) so that I can weld patches for attaching the support blocks and steppers.
I've chosen EM806 drivers. Yesterday I was about to order from AliExpress, thought I'd check Zapp first and Gary has a Black Friday deal on, managed to score 4xEM806 for £340 inc vat and delivery and rather unbelievably they turned up this morning 17hrs after ordering! What an amazing service and at the same or better price than China after duties without the wait.
Steppers are ordered from OMC-stepperonline coming from UK warehouse, should be here in the next few days.
Given the drivers arrived and I already had an enclosure to hand I've started to build up the electronics, PSU parts are from Rapid:
Attachment 26798
I also ordered the tooling plate from Smiths, rather good price, 16x3000x355mm 'offcut' for £274. Loads more than I need for this machine but it is useful stuff to have around. It should arrive tomorrow so I can get to milling the plates.
I'm now trying to decide what to do about the epoxy pour given it really needs a nice constant 20 degrees. The frame is in my un-insulated garage, do I build some sort of insulated box around it and bung a heater in there or do I bring it into the house. Temperature wise the house makes sense, however the frame is very heavy and it is more likely to get disturbed indoors by the kids/dog.
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Re: Joe's 1000x600x200 steel and aluminium router started
Rapid progress! No messing around here! You're making me look like a snail though ;)
For the epoxy I'm in the same situation re uninsulated garage. I waited until summer looking for a week of predicted lows over 10 degrees. I remember something about an 8 degree minimum... When I tried the first time I heated the garage to around 28 - but the reaction is exothermic and excess heat sets it off faster which is very counter productive. The second time I didn't bother and it was much better but probably for other reasons.
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Re: Joe's 1000x600x200 steel and aluminium router started
I've actually burnt myself with epoxy before using the normal hardener not the super slow 209. I was building a fibreglass mold and mixed up about half a pint of epoxy, spent about 5 mins stirring it in a container that was far too tall and narrow and it exothermed, spat on my hand which burnt the skin and I threw it outside, the container completely melted and the epoxy was smoking. Only happened once and I've done this many times, I always mix it in a large shallow container now (like a takeaway rice container), never happened since. Trick is to maximise the surface area when mixing.
Anyway I now have a plan:
I picked up a 40w tubular heater today from Toolstation for £14. It has a thermostat. I will get some sheets of polystyrene floor insulation and build an oven around the machine on the garage floor, then pour epoxy and 'slow cook' at 20 degrees for a week. Wont be until next week as I'm still waiting on the ballscrews before I can finish the frame.
One other thing, I'm wasn't planning to put any levelling feet on this machine, it will be mostly sat on a table/bench so I'll just put some self adhesive rubber pads on the bottom. What do you think? For the epoxy pour I will level it with shims off the concrete floor.
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Re: Joe's 1000x600x200 steel and aluminium router started
All this talk of how to raise the temperature reminds of when I was a Pom! My wife and I are starting some epoxy resin art projects soon and with summer starting in a few days are worrying about how to keep the temperature DOWN to 20C. Overnight lows are currently about 22C just before sunrise and then things warm up rapidly. Highs in the shed/studio go to near 50C at times so the plan is to keep the resin in a wine fridge overnight and start work about 6am, possibly with the air-con already running.
I do plan to build a new epoxy-levelled frame for my router at some time, but that will have to wait until the depths of winter around July next year when daily highs in the shed can be kept reliably below 30C.
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Re: Joe's 1000x600x200 steel and aluminium router started
Looking for some validation of my estop circuit as I didn't need to build one on my last machine, it was all integrated into the servo BOB.
My proposed circuit is a normal start-stop relay circuit with the addition of the EM806 fault signals, is this how everyone else does it?
Attachment 26811
E-stop is NC
Reset is NO momentary
FLT 1-4 are the open collector FLT outputs from the 4xEM806.
K1 is a DPST relay, first pole used for latching, second pole to switch contactor.
K2 is a SPDT relay using the NC contact
Functions as follows:
With no driver fault signals K2 is off and conducting.
E-stop is conducting and in series with K2.
K1 is off.
Reset is pressed momentarily, current flows through K1 coil, latching K1 on.
Now if any driver fault signal switches on, K2 swiches on breaking the path through K1 coil, K1 switches off. If fault clears K1 remains off until reset is pressed.
Similarly if E-stop is pressed this also breaks the path through K1 coil and the same happens.
Any additional NO sources of fault can be paralleled with the FLT outputs. Any other NC sources of fault can be added in series with E-stop + K2.
Thoughts?
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Re: Joe's 1000x600x200 steel and aluminium router started
I've just checked the EM806 datasheet and the fault outputs can be set to normally low impedence, i.e. normally closed. This makes things much simpler as they can just be placed in series with e-stop.
Attachment 26812
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Re: Joe's 1000x600x200 steel and aluminium router started
My plate has finally arrived. The first piece had a bend in it:
Attachment 26839
I think it must have been hit by a forklift in the warehouse. Anyway called Smiths and they exchanged it the next day, the new piece is perfect.
Attachment 26840
I've roughed out some bits for the Z axis on the table saw.
Attachment 26841
I got a deal on this plate because it was originally an offcut piece, however I have way too much material for this machine. I certainly have enough plate to build the gantry entirely from plate and not bother with the extrusion, has anyone done this or know of any build threads (I have looked)?
From plate I'm guessing I would form a channel 160x80 with the back open, question is would this be sufficiently twist proof?
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
devmonkey
From plate I'm guessing I would form a channel 160x80 with the back open, question is would this be sufficiently twist proof?
Obviously it depends on how thick your plate is! BUT channels aren't generally that strong torsion (twisting) wise, a box is much stiffer weight for weight.
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Re: Joe's 1000x600x200 steel and aluminium router started
You are right!
I just used the demo version of shape designer, this is 16mm plate.
Torsion constants, for reference the 160x80 ITEM heavy profile 390cm^4
160x80x16mm channel is 39cm^4
160x80x16mm box is 1400cm^4
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Re: Joe's 1000x600x200 steel and aluminium router started
Something else to think about..... 6" x 3" x 3/8" box section (available off the shelf): Ix = 352, Iy = 1152, torsion constant (J?) = 823 - and about 1/2 the price of Item 160x80, though you obviously have to drill some holes :05.18-flustered: A lot of the slotted structural profiles don't seem to be that amazing torsion-wise, I guess it's because a lot of the metal is a fair way inside the extrusion, whereas in a box section it's all at the outside, where it does most good.
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
Voicecoil
Something else to think about..... 6" x 3" x 3/8" box section (available off the shelf): Ix = 352, Iy = 1152, torsion constant (J?) = 823 - and about 1/2 the price of Item 160x80, though you obviously have to drill some holes :05.18-flustered: A lot of the slotted structural profiles don't seem to be that amazing torsion-wise, I guess it's because a lot of the metal is a fair way inside the extrusion, whereas in a box section it's all at the outside, where it does most good.
Cheaper yes but it's not better unless it's prepped correctly and even then it's much more resonant. The profile is generally much flatter than box steel which isn't flat in any direction and it's less resonant, it's a lot easier to work with and does the job fine.
Torsion isn't an issue until gantry width gets wide and even then if sized correctly profile works fine for routers.
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Re: Joe's 1000x600x200 steel and aluminium router started
So I just did some maths, if 've got all my units correct, a 100N force on the cutter exerted at 300mm below the centroid of the gantry cross section and half way along the 1000mm Y axis would cause a deflection at the tool of approximately:
160x80x16mm channel is 39cm^4 - deflection 0.22mm
160x80 ITEM heavy profile 390cm^4 - deflection 0.022mm
160x80x16mm box is 1400cm^4 - deflection 0.006mm
I guess that 100N is unrealistic and would break the cutter first.
I'm going to have to drill all the holes anyway, is the bog standard 6" x 3" x 3/8" aluminium extruded box section flat and twist free with parallel sides?
I was looking at the Item profile extrusion since I thought it would give me parallel flat sides without having to process it. My mill table is only 700mm long, not quite enough to surface the entire gantry without re-locating the work which is difficult to do accurately in plane.
I'm also sure I've seem some pictures on here of peoples gantries constructed from plate?
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
JAZZCNC
Cheaper yes but it's not better unless it's prepped correctly and even then it's much more resonant. The profile is generally much flatter than box steel which isn't flat in any direction and it's less resonant, it's a lot easier to work with and does the job fine.
Torsion isn't an issue until gantry width gets wide and even then if sized correctly profile works fine for routers.
I was meaning box section aluminium, not steel, I'm aware of the problems with that. The stuff I got was pretty straight, the only error from square was a very slight (0.3mm) but even dip along the middle of the long sides, obviously the die designer didn't get his shrinkage allowance quite right :concern:
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Re: Joe's 1000x600x200 steel and aluminium router started
<deleted... I need to read to the end of thread, not end of page>
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
Voicecoil
I was meaning box section aluminium, not steel, I'm aware of the problems with that. The stuff I got was pretty straight, the only error from square was a very slight (0.3mm) but even dip along the middle of the long sides, obviously the die designer didn't get his shrinkage allowance quite right :concern:
That is interesting, if the box is square to its corners then it is much simpler to skim it flat on the mill.I would need to buy a length in order to check it in the mill with a DTI, Aluminium warehouse if out of stock.
I'm still interested in looking into constructing the gantry from all this spare plate I have.
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Re: Joe's 1000x600x200 steel and aluminium router started
I got mine from Simmal (you might need to email/ring them as they don't keep everything ont' website), I suspect other places like DoRé Metals & Smiths might have it too.
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
devmonkey
I'm also sure I've seem some pictures on here of peoples gantries constructed from plate?
Yes probably seen gantry I've shown built from plate and few others used it or adapted to there machines. It makes for a very stiff gantry,
However, it needs a lot more work compared to HD profile. I've used all methods of constructing gantry's and HD profile is by far simpler with more than enough strength for any Router cutting materials up to Aluminium.
Aluminium Rect section doesn't compare to HD profile in terms of resonance and vibration dampening and this is should be more of a concern than twisting deflection you seem to be chasing if you want a good Router.
There is no cutter you will use that will withstand forces enough to twist a gantry made form any of these materials before it snaps. However, Resonance will affect any cutter and the smaller the cutter the worse it gets. My advice is to Stop chasing twisting etc and look more to lowering resonance if you want a good Router.
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
JAZZCNC
Aluminium Rect section doesn't compare to HD profile in terms of resonance and vibration dampening and this is should be more of a concern than twisting deflection you seem to be chasing if you want a good Router.
That's an interesting point and worthy of investigation. I've saved the impulse response files from a length of the 6 x 3 x 3/8 box, does anyone have a short-ish (~600mm) length of 160 x 80 profile they can lend me to do a comparative measurement?
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
JAZZCNC
Yes probably seen gantry I've shown built from plate and few others used it or adapted to there machines. It makes for a very stiff gantry,
However, it needs a lot more work compared to HD profile. I've used all methods of constructing gantry's and HD profile is by far simpler with more than enough strength for any Router cutting materials up to Aluminium.
Hi Jazz,
Thanks for the advice. Do you have any pictures or wise words on how a 'stiff' gantry was made with plate? From the calculations I did a simple channel from 16mm plate is not sufficiently stiff in torsion at 1/10th that of 160x80 profile.
I'm trying to reuse a set of HGR15 rails left over from another project on the Y. These were originally purchased to replace rails on a much larger machine that had rusted badly, since then that machine has been written off.
15mm rails are too narrow to go over an 8mm slot, this means they will need to be drilled and tapped into the centre flat section between two slots or another plate milled to bridge the slots and then mounted to that. If the latter then it isn't much more work to mill up a front plate as well.
If I already had 20mm rails for Y then the profile would be a no brainer as the rails could be bolted straight into the slot.
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Re: Joe's 1000x600x200 steel and aluminium router started
Right I've made a decision!
I called around a load of my usual aluminium guys, Smiths, Aalco, Blackburns, plus a couple of local metal shops. No one has any 6x3x3/8 box on the shelf (even Aalco who have a warehouse near me about 10 acres in size) and although they could get it I would need to buy a full length. To be fair I didn't try Simmal.
I've built two previous machines using 6x2x1/4 box and they worked fine albeit I had to shim the rails, only very slightly as I didn't have a mill back then and I had to bolt blocks into the ends to bolt into (not required on the 3/8 box). Anyway I'm just going to go with the original plan from the first post in this thread, will order some 160x80 Item heavy clone from KJN tomorrow.
I will first try to just mount rails directly to the central flat on the profile, if this turns out too wobbly I will plate over the slots and fix rails to plate.
Attachment 26845
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9 Attachment(s)
Z-axis parts
I've started milling parts for the Z.
Front plate and rail spacers finished, all fits well. These large plates take an age to mill out on my manual mill.
Attachment 26856
At least drilling the holes accurately is simple with the DRO.
Attachment 26865
Also took a delivery of bolts for the machine:
Attachment 26855
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Re: Z-axis parts
Finished the Z back plate so have now assembled the Z. Everything fits perfectly. All 4 long edges of the large front and back plates were milled in a single fixture so these will all be reference edges for aligning the rails and also tramming the Z on the gantry.
Attachment 26870
Pockets for the ballscrew mounts, these weren't perfect were supposed to be 1mm deep, infact 1.28mm so will need a thin shim between front plate and ball nut holder. TBH ballnut holder is not a precision item, rather it is a cast lump, so probably would have needed shimming anyway.
Attachment 26871
Attachment 26872 Attachment 26873 Attachment 26874 Attachment 26875
I'm now waiting on the extrusion to arrive for the gantry as I need this to measure off for the Y bearing plates, gantry end plates, etc. Hopefully should be here early next week.
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Re: Joe's 1000x600x200 steel and aluminium router started
How do I make the images in these posts larger rather than just thumbnails?
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Re: Joe's 1000x600x200 steel and aluminium router started
Joe,
That's looking very impressive.
Clicking on the thumbnails takes you to the larger versions which, on my laptop at least, are sized to fit the screen. Clicking again will enlarge them to what looks to me to be 'actual pixels' size.
Kit
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
Kitwn
Joe,
That's looking very impressive.
Clicking on the thumbnails takes you to the larger versions which, on my laptop at least, are sized to fit the screen. Clicking again will enlarge them to what looks to me to be 'actual pixels' size.
Kit
Hi Kit, I actually meant how to inline images in posts larger than thumbnails, other people seem to be able to do it.
Machined up the Z stepper plate this morning.
Attachment 26878 Attachment 26879 Attachment 26880
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Re: Joe's 1000x600x200 steel and aluminium router started
Quote:
Originally Posted by
devmonkey
Hi Kit, I actually meant how to inline images in posts larger than thumbnails, other people seem to be able to do it.
I kind of thought that, but those of us who care enough can see your full detail pictures and you look to be a bit busy with something more important than how big your forum images look!
Kit
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Re: Joe's 1000x600x200 steel and aluminium router started
Gantry extrusion has arrived from KJN, it is a real beast. KJN cutting appears very accurate.
Attachment 26902 Attachment 26903
So now I need to decide how to mount 15mm rail to the extrusion. I was considering 3 options:
1. Mount rail directly to extrusion between the two slots, drilling and tapping.
2. Mount rail on aluminium plate which is in turn bolted to the slots.
3. Mount rail directly to slot.
This shows that the profile is not flat across the width which I believe is by design so that the slots pull up to meet whatever you are clamping to them. The slot edges are 0.15mm lower than the centre, the centre and the 2 corners are perfectly aligned within the resolution I can measure with finest feeler gauge.
Attachment 26905
Now I have the extrusion (1) is a non-starter as there is a very slight peak in the centre and I would need to mill it flat which is hard given the gantry is longer than my mill table, although not impossible.
(2) is what many people seem to do and so obviously works but is more work for me.
Can I get away with (3), see picture below, what do you think?
Attachment 26904
I have a 50mm fly cutter, it would be possible given the extrusion is already flat and parallel to fly cut between the high points, would have to tram the mill carefully first.
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Re: Joe's 1000x600x200 steel and aluminium router started
That's serious looking profile! What total length did you get for your £340.24?
Kit
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Re: Joe's 1000x600x200 steel and aluminium router started
I wasn't that expensive, think it was about £130 plus vat for 1100mm.
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Re: Joe's 1000x600x200 steel and aluminium router started
Looking at your pic with the straight edge it looks to me that the slope on the inside of the slot is slightly less steep than the slope from the slot to the outer edge. This would mean that your rail would be slightly canted if you go for fixing option 3).
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Re: Joe's 1000x600x200 steel and aluminium router started
You have very keen eyes! Yes at the slot the extrusion is 0.15mm low both sides, since the outside flat is shorter than the centre flat it must be at a slightly steeper angle. I have measured and calculated the cant angle the 15mm profile would have as 0.055 degrees or 198 arcseconds, does this matter (it will be mirrored on the second rail).
Or should I just man up and hit it with this:
Attachment 26908
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Re: Joe's 1000x600x200 steel and aluminium router started
That's not a lot of angle to be true, and when tightened up it might straighten it a bit more. On the other hand facing off the central flat and drilling holes would give a firmer fix I suspect as you're going into continuous metal, rather than a slot - and as Jazz pointed out with HGR15 there's not a lot of contact either side of an 8mm slot to give friction.
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Re: Joe's 1000x600x200 steel and aluminium router started
I temporarily bolted a length of rail to the slot, it seems to mount extremely firmly and doesn't move (maybe helped by the very slight V angle it is sitting in) but must be slightly canted as discussed above. Will decide whether to face mill it tomorrow, another option is just to mill a few mm each side of the slot so the rail can sit flat, this would also preserve the 3 planar points (both corners and centre) in case I mess up.
I initially wanted to fix the rail to the centre however this does increase the moment between the Y bearing and the Z plate by 20mm which may counter the increased stiffness from the firmer rail mounting.Then again the centre of this extrusion will be stiffer than either slot as it i supported equally whereas the slots are supported on one side by the unsupported corner. No idea really.
In the mean time I spent at least an hour tapping the ends:
Attachment 26915 Attachment 26916
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Re: Joe's 1000x600x200 steel and aluminium router started
If I was living in a densely populated part of the UK I'd be asking if any fellow forum member had a nice flat machine that could mill a shallow slot just wide enough for the rails to fit along the full length of the centre of the profile. Possibly in exchange for HobNobs. That looks to be by far the most rigid place to put them.
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Re: Joe's 1000x600x200 steel and aluminium router started
One of my earlier machines used a heavy gauge extrusion with 2 slots and I used the slot closest to the spindle rather than go into the centre. I think it was slightly crowned across the width as well.
I used a full length steel insert inside the slot (a long thin bar with the edges chamfered) to thread into rather than lots of small t- nuts and this helped pull it flat at least locally.
There probably was an overall angle to the rail but I also had a similar rail on the underside surface which would slope the other way. When these were connected to Y axis assembly it must have preloaded the bearings slightly trying to make them parallel to each other. I didn’t notice any issues and the machine ran for years. You can check on the Hiwin site what misalignment is allowed and compare to your angle.