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luke11cnc
25-07-2011, 11:56 AM
Ball screws I'm so naÔve

As the title suggests what a idiot

I nearly made a big mistake, I was going to just buy some M12 stainless steel threaded bar 304 grade I think thatís right and have it machined to accept the coupling and end and support bearings with a M12 machined block as my ball screw.

But after doing more research on this forum I found that a purpose built ball screw is the way to go.

http://www.ebay.co.uk/itm/3-ballscrews-RM1605-360-630mmRM2005-1100mm-3-couplers-/250493223367?pt=LH_DefaultDomain_0&hash=item3a528f41c7#ht_648wt_905

I am going to order my ball screw set from the above ebayer as most people on here seem to rate him for price but is the product any good and what is the service like

With one set of bearings for the x axis for now

Information and back up from a well supported forum is paramount

James and Luke :heehee::heehee:

Web Goblin
25-07-2011, 12:41 PM
Going from his feedback and what a few others have said his service certainly seems very good. Ballscrews are the way to go. they will be much better than screwed rod.

Ian

Jonathan
25-07-2011, 01:04 PM
I am going to order my ball screw set from the above ebayer as most people on here seem to rate him for price but is the product any good and what is the service like

I've bought from him on 3 separate occasions - couldn't afford to buy it all at once! It's generally quick to arrive, and generally good products. Make sure you get his supported linear bearings/rails. The 25mm rails are better than the 16mm and 20mm as they have another row of balls. I found there was a bit more play in the 20mm. When you've worked out what you need email him and he will list what you need.

It looks like you've chosen 20mm ballscrew for the X-axis. The critical speed of 16mm screw, with the bearing blocks he sells, for 1000mm long is about 2000rpm, 20mm screw is 2600rpm, so with 5mm pitch that is 10,000mm/min and 13,000mm/min. Both are probably plenty ... I would either get the RM2005 or RM1610 as the bigger pitch will halve the rpm. I used RM1610 on my Y-axis (750mm long axis) with a 3nm motor and it'll do 12,000mm/min easily. The backlash in his ballscrews is very low.

(My build log: http://www.mycncuk.com/forums/showthread.php/2288-1.7*0.74*0.4m-Mill-Router-building...)

Watch out for customs charges ... he puts a low value on the item so it's not too bad, but you still have the £10 handling fee from Fedex :thumbdown:


With one set of bearings for the x axis for now

For a 600mm wide gantry you will certainly want two ball-screws to prevent it racking. Or cables in a cross shape like on a drawing board slide ruler to keep both sides moving together.


Ballscrews are the way to go. they will be much better than screwed rod.

Yep, using them increased my feedrate on Y-axis by a factor of 2.5 and X-axis by 4. Not entirely comparing like with like there ... but in general they will go much faster due to the higher efficiency.

luke11cnc
25-07-2011, 01:27 PM
I'm confused now could you please paste a link Jonathan R1610

sorry but I looked at so many my head is now spinning with to much info

Thank you Jonathan

Jonathan
25-07-2011, 01:35 PM
Like this one:

http://www.ebay.co.uk/itm/1-anti-backlash-ballscrew-RM1610-305mm-C7-CNC-XYZ-/250603079365?pt=LH_DefaultDomain_0&hash=item3a591b86c5#ht_561wt_905

... but longer and with end-machining.

wiatroda
25-07-2011, 02:00 PM
but you still have the £10 handling fee from Fedex :thumbdown:


From my last invoice - DHL administration fee- £1.25 + 20% vat as value stated on invoice - sometimes you may pay custom duties if custom officers fancy it :). What is a justification of charging £10-Fedex if somebody else can handle the parcel for £1.25-DHL ????

luke11cnc
25-07-2011, 02:25 PM
I have sent him a email today on this item
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=250854590807#ht_648wt_905

what else is needed to complete the x-axis set up is it just the fitting block that bolts to my gantry ??
bracket http://www.zappautomation.co.uk/mdg16-ball-nut-housing-p-180.html

James

luke11cnc
25-07-2011, 07:17 PM
I have added a reply but it is being looked at by the mod's why??

James

Lee Roberts
26-07-2011, 12:04 AM
Hi James, i have just approved your post above. I dont know why that happened as you have posted more than enough times, is this the first time you have seen your posts require moderation?

Thanks,
Lee

Jonathan
26-07-2011, 12:05 AM
what else is needed to complete the x-axis set up is it just the fitting block that bolts to my gantry ??
bracket http://www.zappautomation.co.uk/mdg16-ball-nut-housing-p-180.html

Cheaper:
http://www.ebay.co.uk/itm/3-ballscrew-nut-housings-nut-brackets-RM1605-1610-nuts-/250724336648?pt=LH_DefaultDomain_0&hash=item3a6055c408#ht_500wt_922

Or I'll make you them from aluminium for less than that. Here's two I made earlier:

4274

luke11cnc
26-07-2011, 04:55 AM
lee the first post I wrote was 17 hrs to be approved and the above reply 5 hrs but I just thought this was the norm

a lot of forum will only let you post 5 or 6 time until you reach a pre-set amount like 50 post to stop people spamming the forum

o'well here's to plain sailing

Jonathan Yes please I will PM you if that's ok

James & Luke

jcb121
26-07-2011, 03:41 PM
While he is good on price, after talking with i2i in person, I've decided not to go with him for my build.

Have a look at Merchant Dice's Supported rail and Zapp's bearing blocks.

while you are there take a look at Zapp's ballscrew and anti-backlash nuts(£21).

it may be a tad more then china, but the pros are :It WILL be straight, it Will be quick and if you have an issue you can return it quickly.

Jonathan
26-07-2011, 05:01 PM
it may be a tad more then china, but the pros are :It WILL be straight, it Will be quick and if you have an issue you can return it quickly.

It's quite a lot more expensive than China, but up to you I guess...
If you order the ballscrews and rails together you wont have any problem with them being straight as the rails are strong and they will protect the screws as it's all packed together. I didn't have a problem with any of the parts I bought not being straight... even the 2100mm ballscrews were fine and they came on their own.

He's generally pretty quick ... despatch in a couple of days and the shipping takes 2 or 3 days.

I got, for £280, two RM2510-2094mm and one RM1610-905mm ballscrew for £280, that's with different end machining too. From Zapp the same would be £478!! Without end machining it's about the same price ... but assuming you've not got a lathe you need that, though I would do it myself.

luke11cnc
26-07-2011, 05:08 PM
here is a image of the router table I'm going to make


4276

I am going to make some changes to it

first change will be the gantry up-rights will be in extrusion and have supported rail on the X-axis R25

James & Luke:smile::smile:

luke11cnc
04-08-2011, 11:42 AM
Just a little update on progress

I have received the following Items

8 SC20UU x 4 pcs Linear Ball Bearing these are for y,z axis
4 SK20 Shaft Support ID20mm Samic
3 X Stepper Motor - 3 Nm, CNC Mill/DIY

and I have ordered the following

three stepper mount for the above stepper motors from Jonathan Thank you Jonathan
Ball screw support ordered again from Jonathan
and -RM1605-1100mm with ballnut and end mached+ a set BK/BF12+1pc Coupler 8mm*10mm(8mm is for motor shaft) SBR25-1100mm(2supported rails and 12 bearing blocks)

Next on my list is the aluminium extrusion but not until I work out the size of my bed
I believe a thread lenght of 1063mm from a shaft length of 1100mm but I haven't decided the (y axis) length yet I think I may go with 700mm witch should give me a cutting footprint of 900x500?

the intended usage of this machine is oak,MDF,pine,acrylic and small amounts of aluminium (and even a plotter cutter for my wife crafting)

I have uploaded Draft sight and working on using it



James

Jonathan
04-08-2011, 12:09 PM
I have received the following Items

8 SC20UU x 4 pcs Linear Ball Bearing these are for y,z axis
4 SK20 Shaft Support ID20mm Samic


You're not using supported rails then :thumbdown:



and I have ordered the following

three stepper mount for the above stepper motors from Jonathan Thank you Jonathan
Ball screw support ordered again from Jonathan
[/COLOR]


Will be ready by tomorrow...


RM1605-1100mm with ballnut and end mached+ a set BK/BF12+1pc Coupler 8mm*10mm(8mm is for motor shaft) SBR25-1100mm(2supported rails and 12 bearing blocks)

12 bearing blocks!! That seems a bit extreme for two rails. I wonder how much difference it would make if you used more than two blocks per rail...

Anyway, centre height of the BK12 block is 25mm and total height of the SBR25 rail and block is 60mm. That means I need to make the centre height of the ballnut mount 60mm-25mm=35mm. Do you agree?

luke11cnc
04-08-2011, 12:23 PM
I may use supported rails I bought these bearings before I found the better priced supported on ebay

I can always use them for a rail guided rip saw later or sell them on ebay

I agree with the height of the mount

i don't under stand why there is 12 bearings I will have to see when they come ?? I thought it was 4 bearings and 2 support bearings for the ball screw ??

O'well looks like I will be going 25mm supported on the Y,Z axis as well or sell the remainder

James

luke11cnc
08-08-2011, 08:46 PM
well it's started, big time.
I bought my aluminium extrusion today just waiting wanting and more waiting for my stuff from china?? But now I will have to wait even longer for the extra ball screw and supports to come as I've decided to add a extra ball screw to stop it creeping as I have read on similar posts I may even up grade to stepper motors from 23 to 34's (but unsure at the moment)

I will post a image later when I have made my bed

James and a excited Luke

Jonathan
08-08-2011, 09:54 PM
But now I will have to wait even longer for the extra ball screw and supports to come as I've decided to add a extra ball screw to stop it creeping

Have you decided to get the next one from the same place?


as I have read on similar posts I may even up grade to stepper motors from 23 to 34's (but unsure at the moment)

I think for the size of your machine it's not neccecary. Remember that since the motor rotors are a greater diameter, their moment of inertia is much greater causing the feedrates / acceleration to be lower ... unless you use a higher voltage. For a size 34 to run effectively you would want higher voltage (mains) drivers. My machine is doubtless heavier, and I've settled with 10m/min rapid feed on the slowest axis - X. It's plenty...though I wouldn't say no to bigger motors!


I will post a image later when I have made my bed

Early night :wink:


and a excited Luke

:smile:

luke11cnc
11-08-2011, 10:28 AM
little up date

as requested by JCB (Jess) some images of the cnc machine.

4336
4337

ball screws and supported rails should be here today or Friday
the extra ball screw, support bearing is on it's way
I am going to add a 90 degree bracket to x-axis and cnc leg so I can put supported rails on the top and ball screw to the underside of the 45x60 profile

Items next on my list to buy

some more aluminium extrusion 45x45 profile for the bed and 40x120(for the gantry uprights

drivers from ebay
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=180601095209&category=71394&_trksid=p5197.c0.m619#ht_3337wt_905

I am in no rush to make this cnc router just yet but only because finding the extra money is a big issue. However I must admit me and my son are enjoying making it together :heehee::heehee:

James and Luke

Web Goblin
11-08-2011, 11:38 AM
Looking good so far. I would add some cross supports near the bottom of the legs on all sides to prevent any movement. The natural movement of the drives will cause the frame to sway and you dont want that to happen.

Ian

Jonathan
11-08-2011, 12:03 PM
Looking good so far. I would add some cross supports near the bottom of the legs on all sides to prevent any movement. The natural movement of the drives will cause the frame to sway and you dont want that to happen.

Ian

Yes definitely, and some triangulation wouldn't go amiss.

luke11cnc
11-08-2011, 12:06 PM
yes that is what the extrusion is for against the wall and Four more 45x45 on the bed

luke11cnc
11-08-2011, 01:26 PM
bits have arrived BUT I'm waiting for Luke to come home so HE can open the package

sorry lad's and girls (if any) but this is a Father and son bonding project

I will post images of items when Luke gets home

He is at work with the wife until 2.00 pm

James (excited and eager):tup::tup::heehee::heehee::yahoo::yahoo:

Jonathan
13-08-2011, 12:10 AM
Here's the brackets I've made for you:

4345

4346

4347

4348

Unfortunately it's 4mm aluminium not 5mm. I was told it was 5mm and didn't check ... hope that's ok :redface:

luke11cnc
13-08-2011, 06:13 AM
they look the dog's b's Jonathan

thank you

luke11cnc
13-08-2011, 05:14 PM
well the ball screw ends where a bit tight.
The big bearing end had to go in the oven and be persuaded with a big adjuster (lump hammer and a socket) but now the lock nut at the end will not go on (yes):redface::redface: i must of caught the thread when I had the persuader in action

not to worry I don't think it's going anywhere or should I have it rethreaded :question::question:

James and Luke

we are going to start bolting down the supported rails on Sunday:rofl::rofl:

Jonathan
13-08-2011, 05:52 PM
well the ball screw ends where a bit tight.

It varied between 11.992mm and 12.000mm depending on where I measured ... so a slight taper.


The big bearing end had to go in the oven and be persuaded with a big adjuster (lump hammer and a socket) but now the lock nut at the end will not go on (yes):redface::redface: i must of caught the thread when I had the persuader in action

Typical, I'd try it and see. If they don't fall off then no problem. On my RM1610 ballscrew (Y-axis) I had the opposite problem yesterday - the bearing was not as tight as yours and I must have not done the nut up tight enough...took me ages to work out what what causing the Y-axis to loose position.



not to worry I don't think it's going anywhere or should I have it rethreaded :question::question:

Bigger spanner!! But first check that the two grubscrews in the edge of the nut which lock it in position are out. Also check the pieces that the grubscrews push onto the thread are not interfering as if they've rotated a little they will stop the nut. I had that problem on one of the nuts that came with the RM2510 ballscrews, so a bit bigger.

I've made the extra 4 brackets - 8mm holes and better finish this time. Couplings almost done too...

Jonathan
14-08-2011, 12:50 PM
More brackets, the two couplings and the ballnut mount (finally) done:

4350

4351

(Sorry they're a bit blurred - the camera wont focus for some reason)

luke11cnc
16-08-2011, 09:29 PM
ok a up date
after prizing my son out of bed and then 10 min's later off his computer we made some progress
and did some work in the garage on the CNC machine

and here is the images of today's progress on the x-axis

we first (me) with the aid of pritt stick glued the printed templates to the 75x75 angle and then centre punched it, as image 1

4363

after centre punch the template was removed and we then drill the angle out with a 6.8mm drill as in this next image and yes that is the young man that is building the CNC machine.

4362

after we drilled the holes (long, long time and lots of oil)

we bolted the bearings to the angle as in this next image

4364

after some choice words we finished and he went back to his computer, great I can get some work done (bless him, dad your drill is much better than the drill at school it would take hours to drill one hole, and we did 16 in 11/29 poor me)

But it was worth it just to see a smile on his little face

any way sitting down and having a coffee i thought how am I going to get two rail square?

this is what I came up with

4361

and after some playing around with G clamps and guide it all worked out fine, smooth movement with NO binding

4365

looking good

4366

WHAT DO WE DO NEXT :question::question::question::question::question: :question::question:

I have one ball screw and the other one is on it's way and Jonathan has cut the support for them both

James and Luke the short one but never ever tell him please:smile::smile:

Jonathan
16-08-2011, 09:49 PM
looking good

Just what I was thinking :)


WHAT DO WE DO NEXT :question::question::question::question::question: :question::question:

Er...rest of the gantry? No idea really, I just did it in any order - gantry first and then the bed etc, but only due to space and it being the most interesting bit! I would get the ballscrews mounted before fixing the rails to make sure they don't cause binding.

I hate to mention 'health and safety', but I've often heard that you shouldn't wear a glove (or any loose clothing) whilst using a pillar drill as what if the glove gets caught on the chuck ... ouch

Web Goblin
16-08-2011, 10:08 PM
Jonathan,
you beat me to it. DO NOT EVER wear gloves when using a drill. If any part of the glove, even a thread, catches in the chuck it will pull your hand then your arm round with it.
The only gloves I ever wear are the thin nitrile ones so that my hands dont get oily. These rip very easily so wont cause you any problems.

Ian

luke11cnc
16-08-2011, 10:21 PM
I agree but

that is what they teach him at school, and I don't know any better?? what am I to do??
James

Web Goblin
16-08-2011, 10:38 PM
James,
you could always point them to this link
http://www.hse.gov.uk/pubns/indg229.pdf

If you scroll down to the section on drilling machines you can read their advice.

Regards

Ian

Jonathan
16-08-2011, 10:52 PM
I think you should complain. Surely they should know better? Even if the drills are not powerful enough to do a lot it's still just wrong. I approve that they do DT in year 6 (or year 7?) as at my school it only started in year 8... but we did go straight onto using the lathes and milling machines :)
The head of department reckoned first years were too dangerous!

luke11cnc
16-08-2011, 11:11 PM
he's already had a year of DT and made a puzzle use a dremel and carved his name in MDF they are using drills, scroll saws, pillar drills and hand tools

I hope to turn him around and do things the right way and the safe way

James

luke11cnc
16-08-2011, 11:17 PM
Jonathan

they have gloves for this and that

smocks and boiler suits ( all with gloves and long sleeved arms)

and not once have I had to supply glasses we have to supply glasses for science
gum shields for sport and a full cricket kit including box and sun glasses even sun tan cream

I think I will inspect the DT department

James

Peter.
17-08-2011, 07:19 AM
I've heard it repeated by rote so many times that you shouldn't do it but so long as you wear the correct type they don't easily get caught. Also, if you don't put your hand in the chuck or bit then it can't get pulled in.

I've been wearing gloves with heavy drilling machinery for 22 years, as they are mandatory in my work. You DON'T want any fabric or stretchy palms, our gloves are nitrile-coated non-stretchy palms and elasticated back. With about 60 employees drilling every day I have never seen a problem related to gloves catching and our drill extensions are covered in stillson burrs.

I always wear gloves when drilling with my bench drill as I don't like getting my hands cut or burnt. For your lad, you could run the belts loose enough to turn the bit but slip if there's a foul-up.

Jonathan
23-08-2011, 10:41 PM
It's been almost a week... how far have you got?

I've done the rest of the brackets.

luke11cnc
24-08-2011, 09:15 AM
Hello all I've been away for a long weekend but back now

I did add the new brackets before I went away but I am waiting for new bolts to arrive I should be ordering my drivers, break out board, power supply today and at the week end my spindle 2.2kw water cooled vhf.

I am waiting for some aluminium for a bracket (Jonathan) I will send you the drawing if that's ok, I will supply material if you just give me a price for milling it please.

next week end I will be buying the rest of the aluminium profile to finish the bed and gantry so with any luck I should be ready for wiring it up in October :heehee::heehee: I really can't wait to start playing with the machine :naughty:

I will post some more images this week and even maybe a Video

work to do this week
fit new bolts to brackets that Jonathan has made (twice because I made the drawing wrong (radius in stead of diameter, I really f#### up)):redface::redface: but they will be used some where
fit ball screw to one side, but drill and tap both side's
fit stepper motors to x-axis
finish supported rails
add bed support rails 45x60 profile

James and Luke:rofl::rofl:

luke11cnc
24-08-2011, 08:32 PM
well not done any think today as I fell out the attic and done my back in plus I think I've broken my little finger

ladders slipped on the garage floor, I will need new ladders now

James:thumbdown::thumbdown::redface::redface:

and I feel a right twat

luke11cnc
27-08-2011, 09:26 PM
oops bought the wrong power supply (only 50w) and I need 70w

so this is up for sale £10.00 but it's not come yet so you will have to wait, just like me

http://www.ebay.co.uk/itm/150592194605?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

James

Jonathan
27-08-2011, 09:51 PM
You want 70 volts, not watts! About 500 watts... it's going to cost more than £12.99 I'm afraid. I'm using a 500VA toroidal transformer with two 25V outputs in series - that gets just under (25+25)*2^0.5 = 70.7V

luke11cnc
27-08-2011, 10:12 PM
Jonathan It was a genuine mistake where can I get the right power supply from

PS
Luke loves his badge big big thank you mate

Web Goblin
27-08-2011, 11:05 PM
James,
I know how that feels. When I was building my new workshop earlier this year I was using ladders for some work on the edge of the roof. I had sat them on top of some of the roof sheets I was fitting. Everything was fine until one of the sheets slipped and the ladder went with it. Felt like right t**t as well. Hope you get better soon.

Ian

Jonathan
28-08-2011, 12:48 AM
Jonathan It was a genuine mistake where can I get the right power supply from

http://www.rapidonline.com/sku/Electrical-Power/Transformers/Toroidal/Toroidal-transformer/82719/88-3840

That one plus a couple of capacitors and a bridge rectifier, which I will already have. I can't find any on eBay at the moment ... that one is a bit expensive.


Luke loves his badge big big thank you mate

No worries :)

wiatroda
28-08-2011, 08:22 AM
Try Farnell as well . You don't pay for delivery. Recently I received Item which wasn't working. Then I contacted them and with no problem they replaced faulty item and arranged and paid for collection of the damaged one. Good customer service.

Jonathan
28-08-2011, 11:19 AM
Try Farnell as well ...

Yes Farnell is good, however in this case I had already checked and they're more expensive than Rapid.

They do have suitable capacitors at a very good price, but I've already got some so that's no problem.

wiatroda
28-08-2011, 11:34 AM
Last time I bought from Rapid ( ages ago) I paid few £ for delivery. Some items are cheaper some not. The same IGBT I needed were cheaper in Farnell and wider selection of them. For me personally not always price matters but service you receive, but this is individual. Small items Farnell posts with Royal Mail , bigger -courier. I was pleasantly surprised when I placed order 2pm and had my components next day in the morning with everyday post. Return: nearly instant reply, next day replaced part and collection. With e-bay shops - they exist today, next week they've gone (maybe exaggerated but true).

Jonathan
28-08-2011, 11:42 AM
I just order from either Rapid or Farnell, whichever is cheapest taking into account postage. Lately I've used Farnell more because, as you say, their product range is better.

luke11cnc
28-08-2011, 01:15 PM
is this the right power supply ?

please look at link

http://www.ebay.co.uk/itm/500-Watt-ATX-PC-POWER-SUPPLY-UNIT-PSU-500W-2-SATA-/110664632852?pt=UK_Computing_PowerSupplies_EH&hash=item19c4204a14#ht_1856wt_905

James and Luke

Jonathan
28-08-2011, 01:21 PM
No, an ATX power supply is a computer power supply so although the power is fine you only get 12V (and 5V, 3.3V and some others) which is not sufficient. You will get a much higher feed-rate if the motors are run on a higher voltage. You ideally want 70 volts.

luke11cnc
28-08-2011, 01:32 PM
I can't find the right power supply on farnell

I found a power supply 500w but only 48v ??

Help

rapid web site is down so I can't look on there

James

Jonathan
28-08-2011, 01:38 PM
I can't find the right power supply on farnell

I found a power supply 500w but only 48v ??

Would be OK, but since your drivers can accept up to 80V it's best to do that. I can't find any on eBay that are above 50V, so I think the best option is the transformer I linked to on Rapid in post #46:


http://www.rapidonline.com/sku/Electrical-Power/Transformers/Toroidal/Toroidal-transformer/82719/88-3840

That one plus a couple of capacitors and a bridge rectifier, which I will already have. I can't find any on eBay at the moment ... that one is a bit expensive.

Annoying that the site is down, but it's easy to get round - just use google cache:

http://webcache.googleusercontent.com/search?q=cache:IJEi6-iYBiAJ:www.rapidonline.com/sku/Electrical-Power/Transformers/Toroidal/Toroidal-transformer/82719/88-3840+http://www.rapidonline.com/sku/Electrical-Power/Transformers/Toroidal/Toroidal-transformer/82719/88-3840&cd=1&hl=en&ct=clnk&gl=uk&source=www.google.co.uk

luke11cnc
28-08-2011, 02:01 PM
Jonathan I will order the one from rapid on Tuesday

Will I need to order anything else for it (box) or will it fit in a old computer case along with my drivers and break out board

James

Jonathan
28-08-2011, 02:08 PM
Computer case will be fine. Wire is cheapest from Rapid:

http://www.rapidonline.com/sku/Cables-Connectors/Cables/Mains-Equipment-Cable/CY-Control-cable/119346/02-1066

(I'll buy the spare from you)

I emailed them and they said 2 weeks to deliver it.

Also for the power supply I'd get a bridge rectifier and terminal strip. I'll find them tomorrow when the site is working. They will also have suitable switches for limit switches.

luke11cnc
28-08-2011, 04:43 PM
cool thank you Jonathan

well Luke has been in the garage/work shop for most of the day drilling the legs ready for the stepper mounts

to say he loved it is a understatement at the end of it I received the biggest hug,smile and kiss ever and as he was walking out the door he turned around as said dad " it's been the best day ever dad I love you"

I've taped the motor mounts with just a couple of mm to go but that's for Monday and Luke to do

Jonathan that jig worked really well

I think I've had the best day of my life as well

James and Luke

JAZZCNC
28-08-2011, 04:46 PM
I have a spare torodal transformer and some 4700-100v caps and probably Br-rec that will get you 70+volts if you haven't bought them yet.
The torod is almost new I think it's 1000va but will have to dig it out to get full specs to be sure then i'll be able to work for you the exact volts + amps.
I think i've got 4x caps which can be wired parallel and If memory serves me I think this transformer and 4 caps was giving me around 76 ish volts and 14A ish.

PM me If this is any use to you and I'll give you my contact details.

Web Goblin
28-08-2011, 06:25 PM
James,
what about something like this: http://www.antekinc.com/details.php?p=317

Ian

Jonathan
28-08-2011, 07:09 PM
James,
what about something like this: http://www.antekinc.com/details.php?p=317

Ian

That would be ideal - it's just a lot more expensive than the one from Rapid, especially when you include postage.



well Luke has been in the garage/work shop for most of the day drilling the legs ready for the stepper mounts

to say he loved it is a understatement at the end of it I received the biggest hug,smile and kiss ever and as he was walking out the door he turned around as said dad " it's been the best day ever dad I love you"

I've taped the motor mounts with just a couple of mm to go but that's for Monday and Luke to do

Jonathan that jig worked really well

I think I've had the best day of my life as well

James and Luke

Sounds good...but where are the pictures?

luke11cnc
30-08-2011, 07:26 AM
As requested more images of the weekends work


439244024401440043994398439743964395439443934403


James & Luke:heehee::heehee:

JAZZCNC
30-08-2011, 10:39 AM
Check your PM's.

Jonathan
30-08-2011, 08:45 PM
The aluminium angle you appear to be using to attach the gantry sides looks a bit flimsy. It can bend quite a lot with forces parallel to the Y-axis. Are you intending to reinforce it? Or perhaps you are mounting the gantry some other way...

Your workshop is looking almost as tidy as mine!

What's in the background of the 7th photo looks ideal for a wind turbine lattice tower :naughty:

Edit: Forgot to say, almost done the ballnut mount.

luke11cnc
30-08-2011, 10:00 PM
Yes Jonathan Image 7 has my display gantry and It's just been sold to help pay for the cnc machine But I may have a length spare would you like one ??

what would you suggest for the bearing support as I was just going to mount the gantry sides to it ??


James

Jonathan
30-08-2011, 10:49 PM
Yes Jonathan Image 7 has my display gantry and It's just been sold to help pay for the cnc machine But I may have a length spare would you like one ??

That's a generous offer... how long is one length and what diameter/wall thickness/material are the main 3 tubes?


what would you suggest for the bearing support as I was just going to mount the gantry sides to it ??

Difficult to say really. I used 100x60x5mm steel RHS which would be better but still not ideal. Aluminium extrusion is almost certainly the best option. You could just use solid blocks, but that's a bit crude and probably more expensive than two small lengths of extrusion. You just need to think of some construction that is strong in that direction.

JAZZCNC
31-08-2011, 12:06 AM
Yes Jonathan Image 7 has my display gantry and It's just been sold to help pay for the cnc machine But I may have a length spare would you like one ??

what would you suggest for the bearing support as I was just going to mount the gantry sides to it ??

James

Hi james,

Please excuse if you have posted this info in earlier because i've not read every post just flipped thru. What are you using for a gantry.? Do you have a general drawing or sketch of the overall machine as you would like it complete.?

I've been looking at the pics and think this the layout your going for please correct me if i'm wrong.
The bed will be down where the MDF is layed in pic 7, gantry it will be driven with twin slaved steppers which I presume will be attached at each side directly to the end of the gantry, by this I mean NO lower gantry cross piece. Presume ballscrew on Y axis.

I'm also presuming the bed and frame are not yet complete thou if yes then I see some areas that would concern me and will definaitly cause problems when machining.

What do you intend to mainly cut with this machine.?

Cheers






From the pics I'm thinking you plan to use the
Cheers.

luke11cnc
31-08-2011, 10:33 AM
Jazz I don't mind recapping:heehee::heehee:

This is the second recap I've done but lost the first one I typed 10 minuets ago:redface::redface:


You are Correct the bed is not finish yet three more length of extrusion to add 45x45 profile. the gantry is moved by two ball screws, two stepper motors and two drivers.

ball screw are to be mounted to the under side of CNC rail show in this photo

4406

Material I would like to cut is Aluminium, oak, maple, MDF and Acrylic

I am building this with the idea of adding a 4th axis for turning wood

Ok the drawings well most of it is in my head and as I'm new to most of the drawing software I'm finding it hard to articulate my self but here is a drawing of the Y-axis

4407

the Gantry sides and supported rails are shown in blue

profiles are as follows
gantry side 45x180 extrusion

gantry rail supports are 45x45 extrusion with a bolted brace in 12 mm Aluminium shown in yellow witch will also be bolted to the gantry side rails to stop twisting and vibration movement

shown in green is the Z-Axis support made in 20x 200mm I have gone for a box configuration as it is a lot stronger than a lot of the open three sided I have seen

the rails are 20mm supported and I may even change the drawing to include a third rail at the back in line with the ball screw attached to the bracing aluminium

the gantry sides will be attached to the angle bolted to the support bearings by no less than six bolts


I do hope this makes sense to you :whistling::whistling:

James

luke11cnc
31-08-2011, 12:15 PM
Drivers and Break out board arrived just ordered my spindle 2.2k and just waiting for a invoice for the rest of my ballscrews and supported rails

end of the week I will be ordering the aluminium for the Y-axis from aluminium warehouse I will be picking up the bed extrusion and some of the gantry extrusion as I have a two week waiting time for the big 180x45 extrusion profile

It's all coming together just water pump,nut and bolts and cable to order now and some bits from Jonathan

Luke is getting excited O'and me as well:naughty::naughty::heehee::lol:

James and Luke

JAZZCNC
31-08-2011, 12:26 PM
Oh if your excited now you better get the adult nappies ready for the big fire up day. :)

replyed to your PM by the way.

JAZZCNC
31-08-2011, 03:34 PM
Hi James, Luke.

Regards the gantry and the way you intend to use the angle, like jonathan I feel this is not enough and will be weak area.
From your rough drawing and the fact you mention using Ali 20mm plate have you thought about using 20mm for the gantry sides and bearing plate.
Doing it this way would let you bolt the bottom extrusion to the bearing plate which the ends would be bolted into the gantry side also the 12mm front plate will be bolted to the gantry side plate all could be located into shallow machined groves for easy setup.
It would save buying the 180x45 which really wont had any extra strength and would be very strong.

I've done a few quick drawings see what you think.! . . . It's could use a bit more bracing etc and could be fancyed up a bit but it should give you the idea of what I mean.


Cheers

Jonathan
07-09-2011, 08:31 PM
This should keep us out of trouble for a while :heehee:

4487

Edit: Just dropped one bit on the lawn and made a hole ... will be in trouble if I do that again!

luke11cnc
08-09-2011, 11:17 AM
Yes Jonathan I can wait

I'm going to install Micro switches on my machine are this the right ones

http://www.ebay.co.uk/itm/AC-125V-1A-Mini-Micro-Roller-Arm-Limit-Switch-5-Pcs-/300594876359?pt=UK_BOI_Electrical_Components_Suppl ies_ET&hash=item45fcd9cfc7#ht_2168wt_1139

Thank you for looking

James

luke11cnc
09-09-2011, 10:00 PM
Well I've received my spindle today and

nobody warned me how heavy they are??

I may even put the spindle in between Y axis for support or is this over kill. I must admit I've never seen this done but how hard will it be

spindle weight is like trying to control a brick on the end of my little finger but that is just my own view

with all that weight at the end of a CNC machine no wonder there is issues with twist

James

Jonathan
09-09-2011, 11:42 PM
Well I've received my spindle today and
nobody warned me how heavy they are??


They're heavy as there's lots of copper/steel in there. Be glad it's 3-phase as otherwise it would be heavier.

Switches:

http://www.rapidonline.com/Electronic-Components/Switches/Microswitches

The best switches (I think) are these, but they're a bit more expensive than the rest:
http://www.rapidonline.com/Electronic-Components/Z-series-microswitches-73549

You don't need the roller.

JAZZCNC
10-09-2011, 02:10 AM
Yes Jonathan I can wait

I'm going to install Micro switches on my machine are this the right ones

http://www.ebay.co.uk/itm/AC-125V-1A-Mini-Micro-Roller-Arm-Limit-Switch-5-Pcs-/300594876359?pt=UK_BOI_Electrical_Components_Suppl ies_ET&hash=item45fcd9cfc7#ht_2168wt_1139

Thank you for looking

James

Don't buy cheap micro switch's for home switch's they wear to fast and not accurate enough. You only need 1 for each axis (2 on slaved axis) so buy decent switch's like honeywell or Telmanique they will pay for them self's in the long run and give hassle free service.

Another thing to beware of with cheap micro switch's for limit switch's (not so much home switch's) is the potential for switch bounce or noise, esp with low voltage, low current setup's that most folks use IE: 5v straight from the BOB. . . This will show it's self as false E-stops.
It's a common ocurrence with cheap switch's due to poor quality contacts and the fact the limit's don't get used very often.
What happens is over time the contacts degrade and become pitted and dirty, this cause's noise on the signal line which can fool the controller(Mach3) into thinking a limit as been tripped or an E-stop occured. This often happens when taking heavy cutt's or on machines that vibrate a lot which make the switch's trembel slightly, when really worn/dirty or very crappy switch's used it can even happen when the machine is stood still or just with spindle running.
Also Another thing regards spindles and really crappy switch's used on low voltage setup's. If using a VFD then it's very likely you'll come across some noise issue at some point making it another good reason to buy decent switch's. (And use sheilded cable)

There are various ways to help stop this, using 24v or 12v for limits is the better way and the way it's often done on industrial machines. Thou for DIY just using decent switch's and tripping the limit switch's every so often helps greatly. . . . Also the use of a small 0.1uF capacitor across each switch helps keep the switch contacts clean by charging up to around 5v when the switch is opened then sending a short high current burst through the switch when it close's shorting the capaictor so cleaning the contacts. If you do this and trip the switch's every so often then the contacts are kept clean and noise free.

Please don't think I'm scare mongering because I'm not and noise on the signal lines is one of the most common cause's of electrical trouble folks have, often they don't even know it and blame somehing else like BOB, drivers or motors. When often it's down to cheap switch's and poor control box setup IE: Unshielded cable or bad earthing practices.

Personally I dont use limit's just good quality Home switch's and Mach's soft limit's.

luke11cnc
10-09-2011, 10:31 AM
Excited going to watch my parts being cut on Jonathan's CNC today taking my Camera so lots and lots of Photo's to bore you with later

James & Luke

poor Luke he's at school until 4.30 so he will just have to watch a video and photo's of it

Robin Hewitt
10-09-2011, 11:06 AM
I'm going to install Micro switches on my machine are this the right ones


Hi James

Microswitches bounce when they close, not when they open.

If you want to avoid bounce, without extra circuitry, set your position when the switch opens.

Do you "do" electronics?

If you want maintenence free precision consider an opto-slot with Schmitt trigger.

If you want zero hysteresis consider a standard, photo-transistor opto-slot and feed it into an op-amp wired as a comparator.

best

Robin

JAZZCNC
10-09-2011, 11:56 AM
If you want zero hysteresis consider a standard, photo-transistor opto-slot and feed it into an op-amp wired as a comparator.




Hi Robin,

Great advice robin, thou you might as well be talking Marshen if folks are not into electronics:rofl:

Don't belive James/Luke are into electronics to that level, did consider suggesting opto switch's but didn't want to cause info overload.! . . . simpler to just say use good switch's and warn of the dangers of cheap bad switch's I thought.:question:

I've considered using opto switch's on my machine when the existing switch's start playing up. . . Thou I'm a bit unsure if they'll be ok due to flying debrie passing the opto falsely triggering switch.? . . How do they handle flying Ali chips.?

My machine must hold the world record for slinging chip's.! . . . They even make it into the house 20yards away.! . . . Thou my boots may play a part.:naughty:

Robin Hewitt
10-09-2011, 12:40 PM
How do they handle flying Ali chips.?

Well, in Martian...

Probably need photo-diodes to pick them up if they have any speed, here's the circuit :heehee:

JAZZCNC
10-09-2011, 02:49 PM
Well, in Martian...

He he spelling ain't my thing.:whistling:

luke11cnc
10-09-2011, 07:47 PM
I would really Like to thank Jonathan for today I really enjoyed my self cheers mate( I hope you don't mind a old git like me saying MATE) BUT YOU REALLY HAVE A FRIEND FOR LIFE.

The postman dropped of a big big doughnut today but no supported rails or ballscrews (bastard)

I will post some video and photos when I've worked it out

James & Luke

luke11cnc
11-09-2011, 06:56 PM
well I've got around to doing the video from Saturday cutting of the Gantry

so here it is (this is my first ever video posting)


oops I have to load it to youtube first


http://www.youtube.com/watch?v=Zou87qbtEPU



and some photos



4516


4518


4519


4517



Jonathan I didn't get a finished photo so maybe you could post some??

sweet I cant believe I got it right FIRST TIME:whistling::whistling:


James and Luke:heehee::heehee:

Jonathan
11-09-2011, 07:49 PM
Jonathan I didn't get a finished photo so maybe you could post some??


Here it is, along with the rest of the bits I've just done:

4520

4521

4522

All done with single flute carbide cutter and 1mm DOC. The first part at 540mm/min and the rest at 600mm/min. Due to the aluminium bar not being flat (even though it's called flat bar!) the cutter on the first pass went up to about 2mm depth of cut at the same feedrate. It was still perfectly happy at that, though a little more noisy. The line on the edge of the first of them was caused by a chip in the cutter. For the rest I was going to use a new cutter, but due to negligence on my part (putting a screw where it was going to cut) it got smashed so I put the original cutter in, and for no apparent reason the machine decided to go and machine a different screw which subsequently melted with lots of red sparks! Hopefully I can regrind that one into something useful as only the last 5mm or so is bad. After that I put the last one I have in which I have reground by hand twice, so the above parts are done with that. Quite pleased that it has still attained a nice finish.

P.S. Is it just me or is the aspect ratio wrong on your video?

JAZZCNC
11-09-2011, 08:58 PM
All done with single flute carbide cutter and 1mm DOC. The first part at 540mm/min and the rest at 600mm/min. Due to the aluminium bar not being flat (even though it's called flat bar!) the cutter on the first pass went up to about 2mm depth of cut at the same feedrate. It was still perfectly happy at that, though a little more noisy.

Nice job there mate(Jonathan), bet luke's getting well excited not to mention Dad. :heehee:

Here's what I cut @ with Ali.

Using a 10mm single flute HSS/Cobalt, (mainly because thats the only size I have with 19mm flutes, other wise normally 6mm) I cut full slot @3mmDOC(33%-Dia) 1000-1200mm/min, 7-10,000rpm depending how happy she's sounds.
If side cutting 0.25-Dia Step, DOC 75%-Dia, similiar feeds/speeds or slightly higher depending how it cutts. Always adjusting feed over-ride on how it sounds or cutts.

Blown air for cooling and chip clearence with the odd squirt of cutting fluid if sticky Ali or hard spots. (Messy as hell with flying chips but no nasty lumps on surface from re-cut and cutters last much longer.)

Then finish with 0.2 full depth finish pass @ 800mm/min 10,000rpm.

Makes me laugh to think that when I first started used to cut 0.3-0.5 max and if really brave I pushed it upto 0.75mm at a scary 500mm/min. . . It was mostly the noise that scared me and I soon found out that I was actually scratching it away rather than cutting and the cutters actually performed better and lasted longer when pushed harder or more to the point at or nearer to there intended chipload's. . . . Much less heat.

luke11cnc
11-09-2011, 09:10 PM
Jonathan I think it's just you

all look's Ok to me

Those parts look really good big thank you see you Saturday I can't wait to start fitting parts to the CNC next Sunday

Luke has sprained his wrist and got it all strapped up (playing Rugby) we had to take him for a X-ray last night Bless him

well the computer is in the workshop and all working ok, how ever I spent all day trying to find a video controller driver as the one with my xp didn't load.It's a good job I have a toggle or what ever it's call

James

Jonathan
11-09-2011, 09:26 PM
Jazz - are those feeds/speeds on your CNC router or milling machine?
I'm using 12600rpm as that's what it sounded best at. I added a little cutting fluid into the slot every so often.



Luke has sprained his wrist and got it all strapped up (playing Rugby) we had to take him for a X-ray last night Bless him

That's why I always did anything I could to avoid playing Rugby! Hope he gets better soon...

JAZZCNC
11-09-2011, 10:17 PM
Jazz - are those feeds/speeds on your CNC router or milling machine?
I'm using 12600rpm as that's what it sounded best at. I added a little cutting fluid into the slot every so often.

On my CNC machine, I don't have a mill.

I used to cut squirting with Industrial WD40 type stuff called workmate 40(WM40. .:naughty:) that I have manufactured and sell in my day job.
This was ok but has the negative affect (like you'll know) of making the chips stick and clog the slot rather than fly away. . . this has 2 negative affect's.(Other than fumes)
1: The heat doesn't leave with the chip.
2: The fluid heats because it's not flooded away so just sits there boiling.
Both together heat the Ali so the chips are warm before the cutter actually cut's, on cheap Ali or if too hot can cause sticky bits or chips which weld them selfs onto cutters.

The best by far is blown air because it keeps all the slot clear and blows the chips away from in front of the cutters path. Thou like I say messy as hell with chips blown all over the place. . . . There's a 10feet perimeter round my machine that looks like it's rained glitter when doing big job's.:lol:

Tried using a mister but I couldn't breath so soon knocked that in the head.

At the minute I've just got 3 simple coolant nozzels connected to regulator pointed at the cutter blasting away all in it's path (Got big compressor)

When I get time(So never) I'm going to make Ali ring sandwich with 8 short directional squirt nozzles, 4 will be air, 4 coolant that fasten to the base of the spindle (Maybe put in some Led's for light as well) then with selonoid's control both with Mach3.
Air will be constant but turned on off by Mach and coolant will squirt every so often just enough to stop sticking but not fume me out the shop like mister.


James: If you think rugby is bad for broken bones try MotoX, I've been in just about every A&E with either my son or me in the hot seat. .:lmao:

Jonathan
11-09-2011, 10:26 PM
You've just described exactly all of the things I've tried (except mister, not tried that) and the same effects!
I agree compressed air is great. So far I've done that just by holding the air gun close and following it which works reasonably well. The main problem is heat getting into the part I am machining - as soon as that gets hot say bye bye to the finish/cutter. Compressed air doesn't seem to be effective in that situation, you need liquid cooling. On the parts I just posted this wasn't an issue as they were cut from a 12"x3/4"x2000mm bar which nicely conducted the heat away.

One day I'll attach hoses for coolant and air...

It depends a lot on the grade of the aluminium...6061 is the best I've used so far.

Going to buy some more 6mm 1fl cutters now.

JAZZCNC
11-09-2011, 11:08 PM
Completely agree agreesive flood coolant is best by far and my next SUPER HD MILL (For diy anyway) will have full "drown if you stand still" coolant and enough air to blow the knickers off a Nun at 50yards.:whistling:

The next best thing I've found for ALi is air but lots of it, don't need high pressure just plenty of volume. . . .This and playing with the chipload/RPM and I tend to find the happy medium.

Best alloy cut so far small amount 7075-T6 for some motor bike engine covers very expensive stuff and scrounged from a mate. . Wish I could get some more.!!

Worst stuff some really crappy 5 series that was like cutting string cheese. . . Night mare.:thumbdown:

Anyway I'm off to watch F1 Grandprix on Iplayer been away MotoX-ing all day so missed it. . . . . Don't even think of telling me who won because I'm not returning after posting this. .:rofl:

Jonathan
12-09-2011, 10:24 PM
Completely agree agreesive flood coolant is best by far and my next SUPER HD MILL (For diy anyway) will have full "drown if you stand still" coolant and enough air to blow the knickers off a Nun at 50yards.:whistling:

LOL

I think the extrusion you've mounted the ballscrew and rail for X on is 45mm tall? The centre height of the BK/BF block on ballscrew is 25mm, you've said 30mm for the ballnut blocks and the SBR25 rails are 60mm total height. So distance between mounting plate for linear bearings and ballnut block is 30+25+45+60=160mm. That makes the distance between hole centers, with 3/4" thick aluminium 160+19.05=179.05mm. Call it 179mm...
The distance between the mounting holes for linear bearings and ballnut mount plate on the gantry sides I just made is 180mm, shall I make the ballnut blocks 31mm centre height to compensate? I know the sides are slotted so it would still work, but still nicer to have it correct to start with?

Edit: reading that again makes me think it's probably negligible

luke11cnc
13-09-2011, 08:19 AM
Jonathan we have slotted holes on the gantry??
and as I said "I did the drawing dimensions off the ballnut support as it is fixed in place" but I suppose I lost a 1mm on the pencil line ??

James

luke11cnc
13-09-2011, 02:06 PM
I now know where I went wrong Jonathan my drawings where based on 20mm material and the material is actually 19.050075 however we do have slotted holes so that should be ok

James

Jonathan
13-09-2011, 06:59 PM
I now know where I went wrong Jonathan my drawings where based on 20mm material and the material is actually 19.050075 however we do have slotted holes so that should be ok

That would explain it yes. The only thing that worries me is these errors/tolerances all add up and could ultimately cause the remaining 1mm clearance you will have in the slot, if I make the ballnut mounts 30mm, to disappear. Still it's probably negligible...

luke11cnc
13-09-2011, 07:06 PM
Jonathan make it with the extra 1 mm as we can always mill it off if needed??

James

luke11cnc
13-09-2011, 10:14 PM
Just a small up date of parts I have

fitted or waiting to fit
4532


4530


4531

4533

as you can see the last photo is the extrusion waiting for Luke to fit

in photo 2 and 3 shows the transformer given by a really nice member of this forum

you know who you are, & a BIG BIG THANK YOU I will find a way of paying you. if not for the item then for the postage you have been warned

Items to get this month a forth stepper and a water pump for the spindle

Items to have machined this month Y , Z-axis supports Ie the 20mm material that connects y to z and z to spindle

belts for y and z plus pulleys and stepper mounts O'my god Jonathan has his work cut out for him

James

luke11cnc
14-09-2011, 06:44 PM
I think I may restart my build log?

what do you think ?

James

JAZZCNC
14-09-2011, 06:59 PM
I think I may restart my build log?

what do you think ?

James

NO It's always nice to see it from the very begining, shows others later how a build is ever changing and just what goes into building a nice machine, which I'm sure yours will turn into.

Leave it be. . is my vote.!

Jonathan
14-09-2011, 07:01 PM
Hear hear.

luke11cnc
14-09-2011, 07:03 PM
OK Jazz it's just getting clogged up with silly comments by me and doesn't look very professorial at all

James

JAZZCNC
14-09-2011, 07:13 PM
OK Jazz it's just getting clogged up with silly comments by me and doesn't look very professorial at all

James

It's not a fashion contest it's diary of your build. It's fine and the silly comments just show your excitment, just wait untill the frustrated comments appear then you'll want to delete the whole machine. . Lol

luke11cnc
14-09-2011, 07:53 PM
OK I will leave it well alone

Luke is really playing on his wrist

JAZZCNC
14-09-2011, 08:10 PM
Luke is really playing on his wrist

Kids who'd have em eh. . Lol

I'll try and dig the Xray out of my lads smashed wrist with pins, screws and titanium rods so you can use it as ammunition to show him it could be worse. . . Maybe also put him off expensive motoX as well if your lucky. . lol (Didn't work for my lad thou.!!)

luke11cnc
14-09-2011, 08:13 PM
Cool Jazz

do you want to see a x-ray of a pace maker??

James

JAZZCNC
14-09-2011, 09:05 PM
do you want to see a x-ray of a pace maker??
James

No thanks and on that note don't be playing with those capacitors.!!

Jonathan
14-09-2011, 09:11 PM
I'll try and dig the Xray out of my lads smashed wrist with pins, screws and titanium rods

Did you get to keep the titatium? Useful stuff...


No thanks and on that note don't be playing with those capacitors.!!

If I'd known I wouldn't have shown him my wind turbine as there's lots of big magnets in that. Field is pretty enclosed so should be fine. I've since moved the big neodymium magnet I had left stuck to my lathe just in case!

JAZZCNC
14-09-2011, 09:16 PM
Did you get to keep the titatium? Useful stuff...


No it's still in there replacing the smashed bit, I've threatened to remove it a few times thou. .Lol

luke11cnc
14-09-2011, 09:25 PM
Thank's people and yes Jonathan I did see the big magnet on the lathe

I had to go for a recalibration this week as I walk through a security point and then realized it was a big magnet one

I'm so lucky it doesn't happen to often:surprised:

I was at the court house(in Leicester) paying a old old speeding fine from March

I now have 3 points on my licence and i was only going to the f***ing dentist
James

Jonathan
14-09-2011, 09:28 PM
I now have 3 points on my licence and i was only going to the f***ing dentist


Speeding to the dentist, that's a bit keen!


Jonathan make it with the extra 1 mm as we can always mill it off if needed??

I will do that.

luke11cnc
15-09-2011, 09:47 AM
Speeding to the dentist, that's a bit keen!


Yes I was really poorly at Christmas (swine flu) and as a result I smashed three teeth as I hit the floor a bit to fast as I past out, But the pace maker kicked in and I came around pretty quick( go job it's working)

I also ended up in A&E at one point as I went over in the dentist (police and ambulance turned up) I felt such a fool.:redface:

The teeth cost me a small fortune £600.00 lab fee's alone glad I'm covered on denplan

James

luke11cnc
18-09-2011, 09:20 AM
well I've tried to get all rails and ballscrews on one plane as suggested and recommended by Jonathan but I can't

Yes yes I screwed up

my gantry is to short

so I have gone with this But I am open to suggestion

4552

I am going to use 50x100 mm extrusion as my main support for the rails and bolted to 6" aluminium

James & Luke

luke11cnc
18-09-2011, 10:32 AM
I think I have cracked it what is your views on this drawing

4553


Extrusion 50x50 mm but the down side is they only do it in light

James & Luke

Jonathan
18-09-2011, 11:55 AM
I think your latest design, but mirrored so that the Z-axis is mounted on to the same plate as the ballnut will be strongest:

4554

That way the spindle is closest to the Y-axis ballnut which should reduce flex parallel to the Y axis.

luke11cnc
18-09-2011, 12:30 PM
It should be the other way around I don't how how that happened ???

Thank you Jonathan

Oops just realized you mirrored it all ready

James

m.marino
18-09-2011, 03:03 PM
James what thickness you using on the plates for Z?

Michael

Jonathan
18-09-2011, 03:05 PM
James what thickness you using on the plates for Z?

It's 3/4" - same as gantry sides.

luke11cnc
21-09-2011, 08:41 PM
Ok my stepper motor covers have arrived but

the stepper motor has 8 wires and the plug for the cover only has 6 pins

are all the wires require ??

do I need to buy new plugs for the stepper motors

James

I will add a photo later as I'm just having my eat

James

JAZZCNC
21-09-2011, 08:52 PM
do I need to buy new plugs for the stepper motors

James

Nah you only need 4 pins wires are joined in pairs so only 4 needed.

Jonathan
21-09-2011, 08:56 PM
The reason they put 6 pins in probably in case you're using a unipolar stepper driver as that requires six wires.

Which covers did you get out of interest?

luke11cnc
22-09-2011, 04:30 AM
here is a link to the covers I bought

http://www.ebay.co.uk/itm/220788176250?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1071wt_1163

James

Jonathan
22-09-2011, 12:37 PM
here is a link to the covers I bought

http://www.ebay.co.uk/itm/220788176250?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_1071wt_1163


It is as I feared, you bought the ones that 'will not fit the SY60 motor'. The motors you have are actually slightly bigger than Nema 23, so Nema24 ish...23 mean 2.3 inches, 34 means 3.4 inches etc...

Maybe they can be modified. At least it looks like you only bought 2 not 4.

luke11cnc
22-09-2011, 01:47 PM
Yes you are right

I may be able to make adapter plate when my cnc machine is running or at worst make new one's when it is finished so not all lost.

at least I have a shell to copy and the plugs are still usable

James

Jonathan
23-09-2011, 12:07 AM
at least I have a shell to copy and the plugs are still usable


Yes they do look worth copying for £20 each...

More parts for you:

4629
4630
4631
4632

The bore of that last ballnut mount came out very shiny. I used a polished carbide tip in the boring bar from APT:

http://www.shop-apt.co.uk/carbide-inserts-for-turning-uni-tip/dcgt-070204-alu-ak10-carbide-inserts-for-turning-ground-and-polished-for-aluminium-uni-tip.html

I didn't do anything special - it was just cut dry with the auto-feed. Would definitely recommend them for getting a good finish on aluminium...

luke11cnc
23-09-2011, 09:01 AM
Now that's looking good Jonathan

Just the gantry side's too do and I've got a long long weekend of work on my cnc

thank you they do look good

James

luke11cnc
23-09-2011, 02:05 PM
I have found the 6 pin connectors on ebay but would like advice on there load rating please before I buy as I seem to f-this up quite often

any way here is the link

http://www.ebay.co.uk/itm/10-6-PIN-MALE-FEMALE-PANEL-CHASSIS-CONNECTOR-KIT-SET-/280741800382?pt=LH_DefaultDomain_0&hash=item415d83e9be#ht_1240wt_1163

Thank you for looking in advance

James

Web Goblin
23-09-2011, 07:07 PM
James,
I think you said earlier that you were using Nema 23 motors(I think the Nema 23 peak at around 4.5 amps )so those plugs and sockets should be fine. You could always mount a little junction box next to the motors and connect them up that way like i did. Saves alot of hassle and time.

Ian

luke11cnc
23-09-2011, 08:05 PM
Ian

I thought they where nema 23 but they are SY60

James

Web Goblin
23-09-2011, 08:11 PM
I think that would be Nema 24 then. Still around 4amps max give or take a tad.

Ian

Jonathan
24-09-2011, 02:09 AM
Yes they are 60mm, which seems to be referred to as Nema 24 though I doubt that's an 'official' size. They are rated for 4.2A per phase in parallel, so those connectors are fine...
I take it they're for the 'control box'?

By the way the CY cable arrived.... so we've got plenty now.

luke11cnc
24-09-2011, 06:37 PM
cool Jonathan I will see you Monday

I can't wait to see all the parts you've made for me and Luke

Luke has a short week this week he finishes school on Friday at 12.30 so we will be in the garage all weekend next week working on the CNC machine

Yes they are for the control box

James

Jonathan
25-09-2011, 11:10 PM
I can't wait to see all the parts you've made for me and Luke

Your waiting is over:

4639
4640
4641

My home, gradually filling up with swarf...

4638

luke11cnc
25-09-2011, 11:42 PM
OMG they look so so cool

thank you Jonathan

Luke is in bed but I will show him before he goes to school

James

Lee Roberts
25-09-2011, 11:51 PM
Luke's going to love watching the machine for the first time !

luke11cnc
26-09-2011, 07:53 AM
Luke has just seen them and said wow are they for my CNC

can't wait until Wednesday,Friday and Saturday to start fitting them.

Luke said "tell Jonathan thank you please dad"

So on that note Jonathan thank you from Luke

James & a big smile on his face Luke

luke11cnc
27-09-2011, 12:15 AM
Now I've had my wings clipped

I'm not aloud to do any CNC work without Luke

so you will have to wait until Wednesday and Friday for up dates

sorry but Luke and MUMMY has spoken

but I would like to say

Jonathan you are a god yes god and not good

as Luke said it he is to good and dad can we do that with our CNC


reply

yes son but not just yet, lets get the machine working first ??

Jonathan again a big big thank you

You have made my son very happy and more to the point thirsty for knowledge

luke11cnc
03-10-2011, 10:10 PM
At long last some parts have turned up.

post office has gone south in my view

but Jazz one out of two items have arrived and Luke would like to say thank you in his own words and in his own hand writing.

so he has written you a short thank you letter just to prove that it is a father and son project


4705:smile::naughty::smile:

James

JAZZCNC
03-10-2011, 10:58 PM
Thank you Luke for the nice letter. Tomorrow I will remake the missing Jigs and send them first class recorded so they don't go missing again.

James would it be ok to make them from thicker 19mm material so long as the step and hole locations are the same.? I'm struggling with thinner material.

luke11cnc
03-10-2011, 11:40 PM
thank you Jazz that's fine

James

Jonathan
04-10-2011, 05:01 PM
Have you mounted the gantry yet? If so why no photos!


Tomorrow I will remake the missing Jigs and send them first class recorded so they don't go missing again.

What are the Jigs for just out of interest?

luke11cnc
04-10-2011, 06:23 PM
Hello Jonathan

I've not done a lot to the CNC machine over the weekend as we where looking a schools for Luke, plus I have two wedding this weekend so I will try and get some photo's up this week as we did strip out a computer ready for the drivers.

The jig is just a location jig for the Y-axis supported rails as I want to make sure they are true and square on the extrusion I also had to have some m10 T-nuts made as the supplier of the extrusion only go up to m8 plus you had lot's and lot's on your plate and with going back to University I didn't like to ask you to do more before you went back.

How are you doing anyway Jonathan I've not heard for you for ages and ages??


I am waiting for some 10mm round bar to help attach the 50x50 extrusion to the gantry sides I will come over not this weekend but next weekend if that's OK

James and Luke (Luke has a thank you card and gift for you just to say thank you(Bless him)):tup::tup:

AdCNC
06-10-2011, 02:11 AM
Jonathan just looking at your nut mounts you have done, nice job i might add.. but i looks like you could do with a de-buring tool, cleans them edges up a lot nicer then the good old file.

http://www.ebay.co.uk/itm/MONUMENT-3020C-BURRING-DEBURRING-TOOL-/310104498660?pt=UK_DIY_Materials_Plumbing_MJ&hash=item4833ab21e4#ht_1217wt_1165

Just a thought ;-)

Jonathan
06-10-2011, 02:28 PM
Jonathan just looking at your nut mounts you have done, nice job i might add.. but i looks like you could do with a de-buring tool, cleans them edges up a lot nicer then the good old file.

Those pictures were probably taken before I de-burred them...either that or I forgot to do it! I've never got one of those tools as I didn't know if they were actually good, or just a gimmick, but since you've recommended that one I guess it's worth a try.
Generally to de-burr aluminium parts I use the edge of a steel ruler - probably not good practice but it's effective. Similarly if it's a hole de-burr by hand with a drill that's bigger than the hole.

Jonathan
06-10-2011, 02:44 PM
I've not done a lot to the CNC machine over the weekend as we where looking a schools for Luke, plus I have two wedding this weekend so I will try and get some photo's up this week as we did strip out a computer ready for the drivers.

I see.


The jig is just a location jig for the Y-axis supported rails as I want to make sure they are true and square on the extrusion I also had to have some m10 T-nuts made as the supplier of the extrusion only go up to m8 plus you had lot's and lot's on your plate and with going back to University I didn't like to ask you to do more before you went back.

Ok, that's true. I think I've got some spare M10 T-nuts as I made a load for my rotary table. Migh be M8, bit late now anyway.


How are you doing anyway Jonathan I've not heard for you for ages and ages??

Er... fine I suppose. Not so much to do now I'm back at University! I've just started continuing my (quite) high voltage stepper driver design/prototype as that's something I can do here.


I am waiting for some 10mm round bar to help attach the 50x50 extrusion to the gantry sides I will come over not this weekend but next weekend if that's OK

That's suits me. By waiting do you mean have ordered or will order soon? If it's the latter then maybe don't bother as I will almost certainly have some.

luke11cnc
09-10-2011, 10:25 AM
Well after a long long week

LUKE has broken his foot now

So I have decided to crack on with the CNC machine

Now the frame is true and square (spent all day Friday doing this) fitted ONE side of the gantry side to my ballscrew but I have some binding on the other side (about 5mm out)

My rails are square and parallel but the gantry still refuse's to play. One side hits the end of the table and the other is around 5mm off (I can force the other side to meet the side at a right angel) but this is not right (every fibre of my body says "no, itís not right") but I am all out of ideas

I am going to look at the bearing today to see if they are mounted correctly (all facing in the same direction) would this throw my gantry out of square??

I am at a loss to where things have gone wrong??

Does it matter if the bearing are pointing in the same way ??

The only two ways I can get the X-axis to run true is to force the right side over by about 5mm or have the table out of square

Iíve just taken some images of the machine and its now only out about 2mm
So I think I was over reacting and it was just crabbing

But I think I would still like a second opinion

any way here we have Luke striping out the old computer (sorry but Luke is in a bad mood :twisted::twisted:(tired me thinks)) not one smile and he told me not to take any more photo's of him


4726 4727


4725 4724



4722 4720

4728 4723

4721 4719

do you like my drives two Bosch drills :naughty::naughty:


today I'm going to tap my M10 T-nuts and start mounting the Y-axis

James:tup::tup:

Web Goblin
09-10-2011, 11:09 AM
James,
it shoudnt matter which way round you mount the bearings. Keep up the work, your doing well. Can you post a photo of where the parts dont meet so we can get a better idea of whats happening?
How do you manage to synchronize the bosch drills:heehee:

Ian

luke11cnc
09-10-2011, 11:42 AM
Thank you Ian I couldn't do it with out help from this web site and it's friendly members

Here is the two images of the x-axis bearings they should be in line but as you can see the right one is not tight to the MDF (about 1.5mm gap) But I can move it by hand.

4731 this is the left side

4732 this is the right side

Is this just crabbing or should it be in line as It's not under any load ??

James

Jonathan
09-10-2011, 11:54 AM
The joint where the 6" wide plate bolts on to the back of the gantry would have to be perfectly square for the gantry to also be square. The distance is so great that the angle on those joints doesn't have to be out by much at all to get 1.5mm out. Also I'd be amazed if the frame is actually perfectly square, so using it as a reference could be misleading. The other thing is the position of the X bearing mount plates and hole positions - they could be slightly out too. All these tolerances stack up, so it's hardly surprising to me that there's a 1.5mm error ... don't worry about it.

If in the end the machine still wont cut square there's ways round it. If it's not much at all then you can position the X-home switches so that mach3 bends the gantry very slightly to square it when it homes. Clearly that's a bad plan if it's out by a lot as it would put a lot of strain on the structure and motors. You can also compensate in mach3 by using 'formulas' which enable you to make one axis a function of another axis. So you just put X=mY in the X formula box where m is the measured gradient / error. The difficult bit is measuring the error to start with as there's no straightforward reference.


How do you manage to synchronize the bosch drills:heehee:

Maybe he's using the steppers as encoders to provide feedback...

luke11cnc
09-10-2011, 12:33 PM
Thank you Jonathan
I feel a lot better now did you get my email?

I think the slight whip on the 12mm gantry support rail is not helping, I should be flat when both extrusions are bolted up to it. I was quite surprised when I offered the extrusion up to it and had to G clamp to get it flat.

all going well but I don't have a M10 starter tap, so I will have to get one in the week.

So a change of plan for today's work I'm going to mount the drivers in the old computer case

after I tidy my workshop/garage up (what a mess but not as bad as yours Jonathan:rofl::rofl:)
James

Web Goblin
09-10-2011, 01:05 PM
Luke,
did you measure the diagonals of your bed to make sure it was square? Its not out by alot.
If you are interested in taps I have some for sale at the moment. Pm me if you are interested.

Ian

Jonathan
09-10-2011, 01:11 PM
You're welcome to borrow taps from me... but long term you might want your own anyway.

I got your email, thanks.

luke11cnc
09-10-2011, 01:38 PM
Thank you for the offer Ian and Jonathan But I have just bought some from ebay

I have a kit tap but it has no starter tap

yes the diagonals are spot on and all the material for the CNC machine has been digitally cut by the supplier

James

JAZZCNC
09-10-2011, 03:11 PM
James if your only 1.5mm out then thats only 0.75mm across the diagonal. If the machine is not bolted securely to the floor then the frame could very easily bend or move this amount just from moving the gantry back n forth.
If you intend to move it around or it bothers you then put some diagonol adjustable tie rods braces so it can be adjusted and held square. I did this with my machine while building then re-adjusted when I eventually found the place in shop it was going to live then bolted it to the floor . Only then did I tighten and true the gantry/rails etc.

Will it affect the accurecy of cut.? . . Well Yes if your working to high precision then this amount would be considered massive but for oridinery woodworking etc then it's acceptable to some degree.?
I say some degree because there's another issue and IMO better far more important reason to find the inaccurecy and square the frame to near perfect as can be.!

Like jonathan says you can effectively cheat and square the Gantry by forcing it square using the motors.!. . . Problem with this route is that it puts components under constant stress, bearings and even the screws are fractionly twisted this over time leads to premature wear or failing. . . . Much better to find the cause NOW than replace parts or worse still be constantly chasing inaccurecys or even missed steps etc from binding as parts slowly wear away losing performance.!

Taking the time now will pay dividends later down, don't fall into the trap of rushing the machine into service only to pay a big price over the coming months.
Promise you even if it takes a few days to sort this inaccurecy now it will save you weeks of hassle and unneccesary expense months further down the road.

Pulling and holding the frame square with Diagonal tie rods (M12 Threaded rod works good) then bolting the frame down BEFORE finally trueing and bolting the Gantry and rails etc makes the process so much easier and accurate without stressing important expensive components like Ball-screws and linear bearings. This way Only frame is then under tension.!

Edit: I know the T nuts did but have any of those Jigs turned up yet.?

Jonathan
09-10-2011, 04:05 PM
I'd only 'force it' square using the motors if it's not much out at all. Depends on the stiffness of the frame. If it's out by more then bolt the frame down as Jazz says and if it's still not good use the formulas in mach3 to compensate as that will completely eliminate any error.

It's just occurred to be that you could purposefully have the gantry built a little out of square, force it with the motors/ballnuts to reduce or eliminate backlash. The pressure on the ballnuts from squaring the gantry would preload both X-ballnuts rather like if you have double nuts with a spring. Clearly if the cutting force is greater than that preload you will get backlash, but for light work it would work. Disadvantage is clearly extra load on the X rails and I suppose marginally more torque required, so feedrate will be negligibly less. I wonder if this is why I have practically no backlash in my X-axis...I'm not purposefully forcing the frame, but I guess it wouldn't have to be much out.


Edit: I know the T nuts did but have any of those Jigs turned up yet.?

Yes they have.

If the bearings are not all the same way it wont affect this. However the force rating of the bearings must be different in each direction as the location of the rows of balls is not symmetrical. I doubt it will make much difference, but you might as well have them aligned so it's even.

JAZZCNC
09-10-2011, 10:07 PM
It's just occurred to be that you could purposefully have the gantry built a little out of square, force it with the motors/ballnuts to reduce or eliminate backlash. The pressure on the ballnuts from squaring the gantry would preload both X-ballnuts rather like if you have double nuts with a spring.

That then would just be a bodge to hide poor workman ship.!!. . . . . . . Plus it wouldn't preload the nut it would twist the nut.!. . Yes the affect would appear the same as taking up backlash but what it's actually doing is twisting Nut body onto the balls which in turn apply force against the screw. Both the screw and Ballnut are not designed to run with forces in this direction so again your forcing the screw and nut to run out of design parameters.. . . This cause's premature wear.

Much better to build right first time IMO.!!



Yes they have.

Aghh Yipee... Thanks for letting me know.!!

Jonathan
09-10-2011, 10:16 PM
That then would just be a bodge to hide poor workman ship.

Or cheap ballscrews - hence why I think my measurement of the backlash might be misleading.


Plus it wouldn't preload the nut it would twist the nut.!

Maybe, maybe not. It depends what's twisting. If you assume the rails are rigid (not quite true for supported rails as they bend upon the support, but not much) then it must be the gantry in between twisting and any force not parallel to the X-axis is resisted by the X-axis linear bearings leaving only the axial force for the nut. On James' machine, clearly the weakest point on the gantry is the joint between the sides and 6" wide cross piece, so that and the cross piece will bend. The ballnut mount and gantry sides are solid so won't bend noticeably. .. etc it's obvious I don't need to tell you.

Not suggesting one should actually do this intentionally. The force ratings of the ballnuts is huge, so I think you'd get away with it. I'd be most worried about the linear bearings.

JAZZCNC
09-10-2011, 11:02 PM
Maybe, maybe not. It depends what's twisting. If you assume the rails are rigid (not quite true for supported rails as they bend upon the support, but not much) then it must be the gantry in between twisting and any force not parallel to the X-axis is resisted by the X-axis linear bearings leaving only the axial force for the nut. On James' machine, clearly the weakest point on the gantry is the joint between the sides and 6" wide cross piece, so that and the cross piece will bend. The ballnut mount and gantry sides are solid so won't bend noticeably. .. etc it's obvious I don't need to tell you.


Yes the Gantry will more than likely twist at the point where the sides meet cross brace at one side but the Ballnut is attched to the side so will twist against the screw unless the screw roates the same amount as the gantry twists. Plus like you say the bearings will suffer the worst.

Either way it's wrong and not recommended.!!

Jonathan
09-10-2011, 11:38 PM
Yes the Gantry will more than likely twist at the point where the sides meet cross brace at one side but the Ballnut is attched to the side so will twist against the screw unless the screw roates the same amount as the gantry twists.

No, as the gantry sides will not twist at the point where the ballnut is mounted. Looking at the machine facing the Y/Z plane from the top it's cross brace, gantry side, X bearings, X ballnut. The gantry sides will twist between cross brace and X-bearings, but not much at all if any between the X bearings and ballnut as the bearings fix it. The twist will be tiny as the sides are very thick/strong aluminium plate. The same is true for machines configured like ours - the gantry 'ends' have the ballnuts mounted roughly at the same level as the gantry, and the X bearings provide support between so there's nothing to twist the screw. If the X-axis linear rails were not there then yes the screw will definitely be twisted, but that's just silly anyway. Imagine resolving each of the forces, any force not parallel to X that could cause twisting must appear as a contact force on the X-bearings and thus prevent twisting as there should be no clearance in the bearings.
In either case if there is any twist on the screw it's going to be a tiny negligible amount and the extra force that would apply is surely small compared to say the force from screw whipping.

JAZZCNC
10-10-2011, 12:06 AM
Don't matter how you try to flog it Jonathan it's simply wrong and not a good way to build a machine. . . Sooner or later the price of inaccurecy and miss alignment of precision components will have to be payed for.!! . . The degree of inaccurecy will be the determining factor to how long it takes . . . . BUT Like Death & Tax's there will be no escaping it.!

Jonathan
10-10-2011, 12:12 AM
Don't matter how you try to flog it Jonathan it's simply wrong and not a good way to build a machine

I'm not trying to flog it at all. I was just pointing out then that it is wrong to say there is any significant twisting force on the screw, and therefore you're only increasing the axial force on the ball-screw which is the same as what would happen if you did it properly with double nuts and a spring. If it wasn't for the large force it places on the rails I see no reason not to do it. It is obvious that there are far better ways to attain low backlash. I mentioned it originally more to point out how it could lead to a false reading of backlash.

JAZZCNC
10-10-2011, 12:41 AM
I'm not trying to flog it at all. I was just pointing out then that it is wrong to say there is any significant twisting force on the screw, and therefore you're only increasing the axial force on the ball-screw which is the same as what would happen if you did it properly with double nuts and a spring. If it wasn't for the large force it places on the rails I see no reason not to do it. It is obvious that there are far better ways to attain low backlash. I mentioned it originally more to point out how it could lead to a false reading of backlash.

Well It wouldn't be acceptable to me or a practice I'd employ on any machine with my name to it.!! . . . . So again we'll have to agree to disagree.

Oh you might want to checkout how proper double nuts are connected and preloaded.? Dont think you'll find meny springs around.?

Jonathan
10-10-2011, 12:49 AM
Well It wouldn't be acceptable to me ... on any machine with my name to it.!!

Same


Oh you might want to checkout how proper double nuts are connected and preloaded.? Dont think you'll find meny springs around.?

I know, but proper double nuts aren't as good as two nuts and springs / belville washers are they.
When I referred to 'double nuts and a spring' earlier I was thinking of doing something like this as it's a simple way of implementing it:

http://www.mycncuk.com/forums/showthread.php/651-Warco-Major-CNC-build-log?p=8924&viewfull=1#post8924

Especially with only C7 grade screws where the pitch error limits how far you can go with double nuts.

JAZZCNC
10-10-2011, 02:49 AM
I know, but proper double nuts aren't as good as two nuts and springs / belville washers are they.
When I referred to 'double nuts and a spring' earlier I was thinking of doing something like this as it's a simple way of implementing it:


Ok as my final comment on this.!! . . Yes and no. Yes Belville washers will apply far more preload but at the potential cost of shortend life.! There is such a thing as too much preload.
So then for that very reason NO it doesn't make them better.!! . . . .They will only be better for shortened period of time, obviously how long depends on Belville force, but they will wear sooner with the ultimate result of a wornout knackerd screw.
If good quality screws with high preload doublenuts are used they will give zero backlash with trouble free service for years, if installed correctly and maintained properly.
Yes they come at an high cost but theres a reason for that, precision costs.! . . . . If it was just a simple case of sandwhich a few Belville washers between 2 std nuts without any consiqences or performance costs then thats what they would do dont you think.?

Anyway all of this is Ballcocks for 99.9% of DIY level machines and certainly cheap C7 chinese screws.

James I appologise for filling your thread with unrelated post's so know I will say no more unless related to your specific build, which this originally kind of did.!

luke11cnc
10-10-2011, 05:09 AM
Dear Jazz thank you for the y-axis jigs they have arrived they came on Saturday.
I would like to thank you for your time and for rushing a second set out The first set are no where to be seen
I can only now confirm this as Luke has only opened the parcel.

I did email Jonathan saying they had arrived but I was not a 100% sure Sorry for the delay

James & Luke

luke11cnc
10-10-2011, 08:28 PM
I've been looking at my gantry all day and some think is not right and after about 3 hours I decided to get my set square out.


and this is what I found

4733
The above image shows that the gantry is out of square by 1.5mm
4734
the above image shows the joint is fitting nice and tight (this is the left side)
4735
the above image shows the gantry is out by .5mm

am I being to picky does it really matter that much that the Gantry is not square

Well I think so

there is no stress to force the gantry out of square as all bolts have been taken out and the rails are not bolted down the only fixings is the three button bolts in the side of the gantry.

Now I have tried to force the gantry square but it is solid and will not move.

I am at a lost and getting frustrated
what is my options Please Please advise what I need to do :question::question:


James

i2i
10-10-2011, 08:53 PM
if you take one side off and measure the depth of the machined groove on each edge to see if the groove is machined level to the face. It may be a good idea to machine the edge of the plate the side is clamping too, to make sure the mating faces are square and flat.

Jonathan
10-10-2011, 09:23 PM
So then for that very reason NO it doesn't make them better.!! . . . .They will only be better for shortened period of time, obviously how long depends on Belville force, but they will wear sooner with the ultimate result of a wornout knackerd screw.

I think the spring method will be better for longer as wear with the double nut will lead to more backlash, whereas wear with the sprung nuts will not have much effect. It will reduce the preload a bit, but you can adjust it so it guarantees that backlash is eliminated. Which is pretty pointless on a router anyway...but I know which method I'll be using when I convert my lathe/mill.
Either way for hobby machines they are used so little (relative to in industry) than wear on the ballscrews/nuts is negligible. If you've used it for long enough to wear out the ballscrews then you've probably made enough money to replace them.

James: That not being quite square is one reason that I suggested you used triangular plates from the X-bearing mount to gantry side. They will stop the deflection.

I cut the slots in the gantry sides on my router as they wouldn't fit on the mill. The bad had been surfaced recently, so they shouldn't be far off ... if you want me to skim the bearing mount plates to get them square that's not problem. I meant to do it anyway but forgot.
Bear in mind SBR/TBR type bearings will tolerate some rotational misalignment, so will it make a difference when the machine is running? I don't think so, but I'd still add reinforcement triangles to make sure.

Web Goblin
10-10-2011, 10:12 PM
James,
I agree with i2i on this one. It might not be the side plates but the cross axis beam. It might not be perfectly square cut or it might be slightly short. If you have bolted up one side and its a bit short it would give this result when fitting up the other side.

Ian

luke11cnc
10-10-2011, 11:14 PM
thank you all Jonathan I will bring the gantry sides with me at the weekend :)

Ian and i2i the cross axis beam is not tight and only has two bolts on each side top and bottom

James

JAZZCNC
10-10-2011, 11:27 PM
I think the spring method will be better for longer as wear with the double nut will lead to more backlash, whereas wear with the sprung nuts will not have much effect. It will reduce the preload a bit, but you can adjust it so it guarantees that backlash is eliminated. Which is pretty pointless on a router anyway...but I know which method I'll be using when I convert my lathe/mill.
Either way for hobby machines they are used so little (relative to in industry) than wear on the ballscrews/nuts is negligible. If you've used it for long enough to wear out the ballscrews then you've probably made enough money to replace them.

Ok jonathan you seem to know something all the top Ballscrew manufacturers in the world don't so get on with it and good luck.!!

James first I would double check the square is accurate.? Those type of wood working squares are not the best for accurecy.! Ideally you want a good engineers square, longer the better.

The gantry is not neccesorally out of square, check the angle between the cross brace and gantry sides.! . . . Are they 90deg.?
Like as been suggested the cross brace could be short or the rebates in the gantry sides could have been cut fractionly deeper than intended creating the same affect.
If the difference is only small then you could easily place a shim/s in the rebate effectively widening the gantry back to original width and/or use them to bring back into square if rebate is uneven depth or wedged shape.?

Because your using round rail you can accomodate this slight angle difference were the bearing plate meets the gantry side. (Easily fixed with with triangle braces like Jonathan suggests)
Thou it's actually not a big problem if the gantry sides are not exactly 90deg to the cross brace because your using round rail. (If was using profiled rails then yes it would be a big deal.)
Yes ideally you would like absolute square and true but So long as the error is not so great that it affects the screws then you'll be ok

Far far more important is the gantry runs square to the X axis.

I say get your self a good accurate square and some shim steel, It's not un-common to have to use shims to bring things into line or back to square so dont consider it a bodge.!
Far better to hold something square with shims than force it square.!!!

Jonathan
10-10-2011, 11:54 PM
Ok jonathan you seem to know something all the top Ballscrew manufacturers in the world don't so get on with it and good luck.!!

All the top manufacturers are aimed at industry where the expectancies (life, accuracy etc) are significantly greater. So if we slightly reduce the life by using double nuts or springs with the same preload it's still going to last a very long time. Most DIY builds don't lubricate the ballnut which clearly is reducing the life expectancy similarly to what we're discussing, however they still run for years... I did consider lubricating mine properly, but when you're rotating the nuts it's easier said than done. Even if you could connect the tube for the oil the oil just flys out.
My comments apply to the C7 screws almost all of us buy where the spring helps compensate for the lead error, not your C1 ballscrew!

James: You can check how accurate the square is by placing 4 equal diameter cylinders in it arranged in a square and measure the diagonals (i.e. placing the caliper across the tangents). If they are equal you know it's good. That's fine in theory... the problem is finding 4 accurate cylinders, bigger the better-I don't advise using your router's rails!

blackburn mark
10-10-2011, 11:57 PM
If you've used it for long enough to wear out the ballscrews then you've probably made enough money to replace them.


thats the way iv been looking at it :naughty:


Ok jonathan you seem to know something all the top Ballscrew manufacturers in the world don't so get on with it and good luck.!!

thats a tad aggressive jazz :eek: .... in this sport there is an element of "art" and "on the cheep" im struggling to knock jonathans logic till i know better..... out of interest has anyone managed to wear out a ball nut in our DIY circle ?
and did they make enough to replace them lol

JAZZCNC
11-10-2011, 12:40 AM
thats a tad aggressive jazz :eek:

No "Your talking bo@~#cks Jonathan" is Agreesive but I didn't say that did I.:whistling:

Yes I've worn out a ballscrew, it took 3 yrs and yes it payed for it's self meny times.

Jonathan
11-10-2011, 12:49 AM
Yes I've worn out a ballscrew, it took 3 yrs and yes it payed for it's self many times.

You wore out the ballscrew, or the nut and what machine? Did you replace one or both out of interest? Tell me more!

JAZZCNC
11-10-2011, 01:41 AM
You wore out the ballscrew, or the nut and what machine? Did you replace one or both out of interest? Tell me more!

One of the X axis screws on my machine, it was the screw mainly but the nut was well tired. In it's defense I've abused them and the hole machine to the point of torcher.
99% of the time it's cut aluminium and with absolutly no protection for the screws from chips and flying debris. . . Some times running constant for upto 36hrs non stop.
It also didn't help that in the very early days I forgot to tighten one of the pulleys and it came off. The other screw kept going and very badly racked the gantry bending the screw.
I had it straightened but it was never the same.

Got some nice quality 25mm Ground C3 doublenut screws for my new soon to be machine. The old machine will be retired to just cutting wood an plastics.

blackburn mark
11-10-2011, 02:13 AM
Yes I've worn out a ballscrew, it took 3 yrs and yes it payed for it's self meny times.


splendid :smile: .... i can live with that, i give mine an injection of grease now and again and they are pretty clean most of the time :whistling: if i cant make em pay in three years ill go back to wiping backsides for a living :)

luke11cnc
16-10-2011, 09:12 PM
Hello all

Well the day started of well and it was nice to see Jonathan again
I hope you liked your Hand made card and bits.

I have got a lot of bits sorted out to day BUT as always one step forward and five step's back.

My latest problem is this my gantry is 1003mm wide and with a ballscrew of 1000mm in length all look's fine on paper until you add a the belt pulley that is.

I bought the ballscrew with a standard length on the stepper end of 12mm and need 25mm.

disaster disaster two options open to me well three really

Fuck it and sell the lot

buy a new ballscrew with the correct matched machined end or make it fit.

the way I feel at the moment I could just sell the lot or just throw it away

who need this crap anyway


Sorry Just venting because I'm mad at my self and the wife has been on my case

James:thumbdown::cry::cry::cry:

Swarfing
16-10-2011, 09:24 PM
Lengthen the screw is not that hard if you access to lathe. Dose the nut travel the whole length of the screw? I bought a shorter screw to save a few quid and did just that. So don't panic mister mannering.

Jonathan
16-10-2011, 09:35 PM
I got mine all machined to 25mm.


Lengthen the screw is not that hard if you access to lathe.

That'll be my lathe then.

I've done that before to add a handle to lathe leadscrew - drilled & reamed a hole in the end then machined a bar to fit. Put a straight knurl on the bar to make it grip, loctite and big hammer to 'press fit' it. Start by machining the bar slightly oversize, then after put the ballscrew in lathe, get it on centre and skim the bar the right size so that it is on centre.

Can't the whole screw be moved along and the bearing mount on the non driven end be moved?

Swarfing
16-10-2011, 10:20 PM
Your almost right Jonathan? The screw is very hard and can easily crack (only the centre is soft). If this is added to the floating end then no need to knurl it, just go for a nice tight slide fit and let the loctite do it's job.

Web Goblin
16-10-2011, 10:40 PM
Jonathan,
I cant see how the nut will travel the whole length of the screw either. I think your idea of moving the "pulley" end bearing a bit further in towards the floating end and you can machine the plain section down for him to accept the pulley. I dont think lengthening the shaft would be agood idea particularly if you are going to fit a pulley on the lengthened section. Without some kind of support this will start to wear and wobble.

Ian

Swarfing
16-10-2011, 11:25 PM
You wouldn't fit the pulley on the lengthened end? you would put it on the machines end end keep the nut housing to the side closest the belt end. That is how i have my arrangement and it allowed me to add a 90mm extension to the screw.

Jonathan
17-10-2011, 12:00 AM
Your almost right Jonathan? The screw is very hard and can easily crack (only the centre is soft). If this is added to the floating end then no need to knurl it, just go for a nice tight slide fit and let the loctite do it's job.

The reason I knurled it is because that's what John S does. Well, says he does at least. Could anneal the very end of the screw to stop the risk of cracking, but that's probably taking it too far.

Putting the extension on the 'floating' end sounds good to me as all it's doing is stopping the screw whipping, not transmitting torque. The other end is probably easier though as the tolerances to fit the pulley are not tight as for a bearing. It depends how much we need to add?

Swarfing
17-10-2011, 12:08 AM
Jonathan the problem wih extending the belt end is as you have pointed out to is torque on the jointed section. As WG said that end can always be machined to allow for the pulley. An even easier solution is to just extend out the floating bearing housing with some ali round bar and mount the bearing in the end?

At the end of the day the KISS approach is always best, less to go wrong

luke11cnc
17-10-2011, 08:02 AM
I haven't got a clue what your all taking about but I think I've solved the problem.

If I take the retaining nut off and have the pulley machined to slide over the threaded part and have 2mm machined of the pulley shoulder and fit a grub screw plus slide the other bearing right to the end and cut off the excess ballscrew material It will fit

4746

what do you think is this a solution or am I making more problems for my self

James

luke11cnc
18-10-2011, 10:21 AM
No one with any advice on my solution ??

James

i2i
18-10-2011, 11:19 AM
I take it you're going to replace the bearing clamp nut with a thread in the pulley. If so you'll need a more positive location for the pulley, one grub screw just won't be enough. Possibly a pin right through the pulley and shaft when it's clamped up tight.

luke11cnc
18-10-2011, 02:09 PM
Well after a lot of soul searching I've decided to take it down to my local engineering shop and have it rematched if it doesn't work I will have to buy a new one but I'm not going to cut corners to make it work now

and if it works they can do the other one (z-axis) as that is the same

James

Jonathan
18-10-2011, 02:17 PM
take it down to my local engineering shop and have it rematched

Rematched? Wont they charge a lot :(


if it doesn't work I will have to buy a new one but I'm not going to cut corners to make it work now

I'll buy the old one if it is spare, then you don't loose out. Just need to get ball-nuts for it and that's my milling machine X and Y sorted. I need to do the end machining myself for that anyway.


and if it works they can do the other one (z-axis) as that is the same

What is the overall length of the Z-axis screw?

luke11cnc
18-10-2011, 08:53 PM
Jonathan the length of the z axis is 400mm

and yes if a new y-axis is required then you are welcome to it


James

luke11cnc
26-10-2011, 08:25 PM
Just to let you all know the build is back on


Luke is walking now with shoes on so I'm getting him in the garage at the weekend to work on his CNC machine.

we have so much to do and I am hoping to get the machine up and running by the end of November

James and Luke

luke11cnc
02-11-2011, 10:06 PM
well we did do some work on the CNC Machine at the week end and have now mounted the gantry support extrusion to rear beam and gantry sides

4809

poor poor Luke "Dad how many more time do we have to take it apart just to build it back up again"


4808

at the week end we also started the mounting of drivers in the old computer


4811

Now I must admit I did most of this and Luke just did the last one and as you can see he finished mounting the transformer

4810

In this image Luke is drilling out the y-axis supported rails as they came blank

4812

I'm hoping to receive the y-axis supports from Jonathan on Saturday

so we can fit them on Sunday as Mum is out for the day

any way I just thought I would post a quick update

James and Luke:wink::wink:

Ps

it's Luke's bday next month any suggestions for a CNC related present ??

JAZZCNC
02-11-2011, 10:38 PM
it's Luke's bday next month any suggestions for a CNC related present ??

How about one of these. ? ? http://www.youtube.com/watch?v=llRbUHVjP7Q&feature=related

What date is Lukes B-day.?

luke11cnc
02-11-2011, 10:50 PM
cool a bit out of my price bracket

1st December and he is 11

live he lives that long Lol

James

luke11cnc
03-11-2011, 01:51 PM
Hello Jonathan

thank you for replying to my email

here is the image I said I would post for you'r reference

4815

I would like to recess these bolts into the gantry sides please 10 holes in total

I hope you understand now ??

James and Luke

James:lol::lol:

Jonathan
03-11-2011, 01:59 PM
How about one of these. ? ? http://www.youtube.com/watch?v=llRbUHVjP7Q&feature=related


I have watched that too many times.



I hope you understand now ??

I see ... yes can do that, but is is really necessary (might be a bit awkward to set up)?

PS: Don't let Luke do the bolt up too tight on the transformer because that may damage the windings.

luke11cnc
03-11-2011, 02:16 PM
No I suppose not but I will have to make the stepper mount bracket to accommodate the bolts

James

luke11cnc
03-11-2011, 02:34 PM
found a bday present for him

http://www.maplin.co.uk/robotic-arm-kit-with-usb-pc-interface-266257

James

JAZZCNC
03-11-2011, 08:36 PM
found a bday present for him

http://www.maplin.co.uk/robotic-arm-kit-with-usb-pc-interface-266257

James

Give up your not kidding anyone.!! . . . . WE KNOW IT'S FOR YOU.:dance: . . .Can I have one Dad.:lol:


I have the proper clamp for that transformer if you need it, didn't realise I hadn't sent it.!

luke11cnc
05-11-2011, 10:17 AM
yes Jazz you might be right

I was thinking more along the lines of copying it in aluminium but bigger and more lifting weight as it only lifts 100g max

even to the extent of copying the electronics so we have two

do you think this is do able ???

clamp would be good Jazz

James

luke11cnc
12-11-2011, 09:47 PM
Well today I've been over to see my very good friend Jonathan

and I lost a lot of money with out placing a bet or dealing a card
only joking mate

It still astounded me how much knowledge you have in your sweet head and put us fossils to shame.

I really wish I had a friend like you Jonathan growing up.

Any way Luke has just about given up on the CNC machine ďDad you will never finish itĒ I mean to prove him wrong


All the parts fit apart from the bearings on the supported rails But not a problem I will take them down the road and have them re-cut.

What a twat I am I gave you the wrong ballscrew mount but never mind I will have the mounts machined Jonathan

I will post more Photoís this week and even a video of what to look out for when new members decide to build there own machine

James:rofl::rofl::wink::wink:

luke11cnc
15-11-2011, 07:53 PM
well I've been in the garage again today and fitted a little bit more to Luke's CNC and I must admit it is coming together rather well.

4852

The above image shows some items made by Jazz.

the M10 T-nuts work really well I could of gone with the M8's you can buy from JKN but I wanted to spread the load area a bit more.

I am also pleased with the supported rail clamps/guides that Jazz also made me shown in the above image they keep it square and true while Luke drills them.

James:tongue::tongue:

Jonathan
03-12-2011, 08:20 PM
Z-axis is in progress, plus Y-axis stepper motor mount:

5003

5004

5005

I reground the cutter (6mm single flute) freehand after the Z-plate as it was chipped. Better finish than ever! :surprised:

5006

All the bits made, mainly drilling and tapping to do now then check it all fits properly.

So close now :smile:

Something worth noting for the future is that the aluminium flat bar is nowhere near flat, so in future I will stick with getting aluminium plate like I used for my machine.

The BK support is partially dismantled in the photo as it's not going to work without modification. Glad I never considered using them on my machine, too much trouble compared to just making the whole thing.

luke11cnc
08-12-2011, 11:16 AM
Just a small up date the x-axis ballscrew has been re-taped and put back on the machine Thank you Jonathan

99.9 % of all components have been made so more images are due this weekend :naughty::naughty:

Jonathan has agreed to come over on the 19th to wire up the CNC Machine so in short 12 days and my machine should be cutting (Christmas is coming early) :toot::toot:

James and Luke:smile:

m.marino
08-12-2011, 11:21 AM
Good to hear folks and hope you have lot's of safe fun designing and cutting stuff on the gantry Router. Best wishes and have a very Happy Christmas Season.

Michael

luke11cnc
11-12-2011, 11:47 PM
O my god o my god

I've seen it my z-axis running by a stepper motor up and down up and down thanks Jonathan

and I say

bring on the 20th, let me complete the cnc machine and play

I've already started to get prices on the 4th axis and will be ordering parts in three weeks

barley twists here I come

James and Luke

luke has started drawing his creeper ready for the cnc machine (bless him)

Jonathan
12-12-2011, 01:16 AM
Few more bolts / holes and it's done:

Y-motor mount:
5051

Z ballscrew fixed end, slightly unusual motor mount. Had to make longer spacer for the bearing support as the existing one wasn't long enough and caused far too much friction.
5050

My router is accurate, but alas still a bit off square:
5052
5053
5054
5055
Made a quick nylon seal for additional protection as that bearing gets the most dust being right above the cutter:
5056

Will post a video and more info tomorrowish.

luke11cnc
12-12-2011, 05:59 AM
they look amazing Jonathan

But image 1 the bracket is inside out, motor needs mounting on the other side Hee Hee

James

Jonathan
12-12-2011, 09:20 AM
But image 1 the bracket is inside out, motor needs mounting on the other side Hee

Oops, yes it does. It fits on both sides.

luke11cnc
12-12-2011, 11:49 AM
Jonathan do you think we could make that third leg/mount adjustable ??

James

luke11cnc
12-12-2011, 12:02 PM
So it look's a bit like this:tup:

5062

Please note Jonathan this is not to scale:rolleyes:

James and Luke

Jonathan
13-12-2011, 04:34 PM
Yes I can and will change that.

http://www.youtube.com/watch?v=O4o6tNXnT9I&feature=youtube_gdata

Putting the DTI where I did to start with is a bit pointless, but using it to test the runout revealed the runout is 0.06mm measured about 10mm from the chuck, which is poor. It increases linearly with distance too ... so the cutter is held at an angle to the axis of rotation. I measured inside the spindle bore too, and it's the same.

jcb121
14-12-2011, 10:51 AM
Luke, What are you using for the bed of your machine?

For mine I was thinking 20mm Aluminium but I'm swaying more towards 10mm or 15mm due to Cost of water cutting, postage and materials.

Unlike mine you have a frame though....

JAZZCNC
14-12-2011, 12:03 PM
Luke, What are you using for the bed of your machine?

For mine I was thinking 20mm Aluminium but I'm swaying more towards 10mm or 15mm due to Cost of water cutting

Depending on the frame support centre's on your bed then I wouldn't go less than 15mm.!
If you look at the link below you will see my bed made from 16mm strips with 10mm gaps spaced at 45mm centres and the support beams are spaced approx 400mm centres.
Overall it works great and soon will be upgraded again which hopefully will make it just that bit better. The bed (which is adjustable height) will be removed and a stainless steel box fitted underneath so mild flood coolant can be used and will filter and catch the chips which will be dumped into a collection bin.

If doing again I'd lessen the support beam centres to 300mm and use 20mm strips, that said the 16mm works great just feel 20mm would give it that bit more meat allowing for a longer lasting bed after it as been surfaced a few times. With 16mm the distance from the clamping boltd head to surface determines the amount of usable bed surfacing.
Thou unless some major coding cockup goes on it will be years before that's a problem.!!. . .that said it only took me 2wks before I'd drilled a nice 6 hole ballnut pattern into.:redface:
http://www.mycncuk.com/forums/showthread.php/3661-1st-Build-Second-machine/page8

Edit: The reason I used strips was 2 fold.
1: cost of plate Ali too much wonga
2: Didn't like the thought if a major cock up happened then the whole plate was screwed up, with strips I just replace any that get damaged if I have a brain fart when coding or machine goes on rampage.! It also made slots for T-nuts easy.
( By the way I use the 10mm T-nuts for KJN profile because the drop between the slots and when twisted self lock which means I dont have to have an access point at either end of the bed like you do with STD T-nuts on a mill making clamping anywhere on the bed easy.

luke11cnc
14-12-2011, 12:38 PM
Jes for now just a sheet of MDF Untill after Christmas but then I will be fitting this

http://www.aluminiumwarehouse.co.uk/p16210/Aluminium_Flat_Bar_-_Imperial_Sizes_(6082T6)_1_in_x_%3Csmall%3E%3Csup% 3E5%3C/sup%3E/%3Csub%3E8%3C/sub%3E%3C/small%3E_in/product_info.html

with a 10mm gap for t nuts

James

luke11cnc
14-12-2011, 01:28 PM
5064

this will cost me £160.00+vat

9@4000
1@2000

James

Jonathan
14-12-2011, 02:17 PM
I was about to post saying see what Jazz has done for his bed, but luckily refreshed the page...
I'm intending to do the same with some sort of tray underneath so I can use coolant efficiently.

Jazz, it sounds like you don't put anything between the part you are cutting through and the bed, just let the cutter mark the bed and surface it occasionally? It must take a long time to cut the surface considering it's aluminium. I surface the MDF at 8m/min but you're not going to go that fast on aluminium!

At the moment my bed is made from MDF and pine, it's a grid of 3x1 PAR wood with 18mm MDF on the top and 9mm underneath. That's clamped on top of two steel rails (box section), which mount to the frame for adjustable height. I've only changed the height once in the past 3 months...
It's like that because before I made the steel frame for my machine the X-axis rails mounted directly on to the bed, so the bed needed to be rigid.


Jes for now just a sheet of MDF Untill after Christmas but then I will be fitting this
http://www.aluminiumwarehouse.co.uk/p16210/Aluminium_Flat_Bar_-_Imperial_Sizes_(6082T6)_1_in_x_5/8_in/product_info.html (http://www.aluminiumwarehouse.co.uk/p16210/Aluminium_Flat_Bar_-_Imperial_Sizes_(6082T6)_1_in_x_%3Csmall%3E%3Csup% 3E5%3C/sup%3E/%3Csub%3E8%3C/sub%3E%3C/small%3E_in/product_info.html)
with a 10mm gap for t nuts

That gives you a roughly 71% aluminium (29% air...) bed, compared to 78% for Jazz's 35mm(?) strips. Not much less to be fair, but more frequent clamping slots, so only slightly weaker but as Jazz says he'd prefer them to be thicker anyway. Probably not much in it, but something to think about.




this will cost me £160.00+vat

9@4000
1@2000

That's 840mm wide which is 24 strips and you can get 3 strips per 4m length, so surely that's only 8@4000 (still £160). Or were you thinking of using the other bits for the perpendicular pieces underneath?

luke11cnc
14-12-2011, 03:08 PM
so would you recommend using 3/4x7/8 19.05x15.88mm then Jonathan ??

switches and cable ordered Jonathan

James

luke11cnc
14-12-2011, 03:26 PM
5065

Looking at the price list Jonathan I may go with 20x20mm so I have 5 or 6 mill worth of surface trimming so it should last me quite a while

what do you think ??

James

Jonathan
14-12-2011, 03:31 PM
It makes sense to use thicker, so yes 20mm. However I'd be inclined to use wider than 20mm strips (only 67% with 20mm and 10mm gap) for additional strength. It's less work to 40x20 compared to 20x20. If you went to maybe 40mm wide you can get two bolts side by side in each strip which should be stronger - less twisting? Not sure...

luke11cnc
14-12-2011, 03:36 PM
good point Jonathan

James

JAZZCNC
14-12-2011, 09:23 PM
Jonathan: Yes I do always put something between the bed and part. Depending on the job at hand.?
If it's a non critical job that the top surface be exactly parallel to bed or thru drilling then I just use any thing to hand that resonably flat IE MDF off cuts.
If it's more important it's parallel to bed but doesn't need to be exactly 100% perfect and doesn't have any drilling involved then I use a 1mm thin ridged card board I bring from work that doesn't compress.
If it has to be exactly 100% perfect and must cut thru or involve drilling then I have several sized 15mm HDPE slabs that I clamp to the bed then surface. MDF is no good for this because the minute you cut the top layer it turns into a shape shifter and no matter what folks think MDF aint flat or parallel thickness.
To be honest 60% of the time the card board is used 30% MDF 10% HDPE.

That said regards MDF.? I've just been given an MDF type paper product sheet that is resin impregnated. It's used to make the cubicles in swimming baths and shower area's. It doesn't swell no matter how wet, even when submersed under water. This I know to be true because this sheet was outside for 8mths.
I've just used a piece as a spoil board and it machines like plastic and surfaces with a perfect finish because of the resin.
Really it's the perfect product for a long lasting disposable bed topper.! . . thou I do understand it's very expensive.

James: (Or anybody who's interested)

Here's how I did it. (It was a bit tedious but worth it) . . . . Material 1"1/2 x 5/8 (38.1x15.88mm)

Using a 90Deg spot drill in the spindle find the centre of bed and scribe boxsection. Then mark the first strip exactly in the centre then bolt down exactly in the centre of the bed lining up with scribed mark.
Then using a 8mm spacer working out both sides bolt down each strip to bed. Then using a 8mm twin flute end mill create a climbing milling toolpath to cut the 10mm slots in 2 depth pass's, didn't want to use a 10mm endmill as it would have been cutting on both sides and required much less DOC taking longer and leaving a worse finish. . . .(Yes I know the 8mm cuts on both edges but only on the way up not down.)
Reason I did it this way was because I have some machine clamps that use 45mm centres. They could have been just butted with a 10mm spacer but there are other bennifits to machining the slots for me(see below). . . . Plus the strips arn't exactly straight.!!

Doing it this way I know exactly that all my slots are exactly parallel to the X axis. Across the very top (Yaxis) and down the outer edge (X axis) as a strip that bolts on top of bed and acts as referance edge, which again is machined parallel and square. I've made some 45mm wide aluminium strips (various lengths from offcuts) that have a 3mm notch down the centre with the edges machined parallel that fits tight into the slots and can be used as positionable reference edges anywhere on the bed ( WHY.? Because I like to cut in differant parts of the bed to save wear on the ballscrews from always cutting in the same spot.)

James I would go with the 3/4 or better still 1" the little extre expense will be worth it.

luke11cnc
15-12-2011, 10:57 AM
Thank you Jazz

Yes I will go 11/2x1
James

Jonathan
17-12-2011, 09:29 PM
Useful ... yes MDF is not flat, but then again it depends what tolerances you're trying to work to. That resin impregnated sheet sounds worth looking in to.

For me to cover my bed with 1.5x0.75" and 8mm slots would cost £475 even taking into account the 7.5% discount they give you for spending too much! Not really happening, though it would be a big advantage I can't really justify spending what my lathe cost on the router bed, could get a 60W laser and power supply for that :naughty:. I guess I could just do half the bed (1000*910mm, or 2000*455 but probably the former) and leave the other half MDF. As long as I skim them both equally that won't loose much, except it means I'll start using one end of the X-ballscrews much more than the other but that's not the end of the world. Would put a sheet of 3mm aluminium underneath half the bed to act as a coolant tray.... got a spare coolant pump.

Anyway, I'm going a bit off topic there. I've put the slot in the mount as requested and the Z-axis is very close. Done a little wiring on the control box too.

JAZZCNC
18-12-2011, 01:03 PM
Useful ... yes MDF is not flat, but then again it depends what tolerances you're trying to work to.

Yep thats why I said "Job dependent"



. I guess I could just do half the bed (1000*910mm, or 2000*455 but probably the former) and leave the other half MDF.

Yes thats not a bad idea. . . I actually do put MDF full length down one side sometimes for jobs that are awkward to clamp or drilling and obviously don't need flatness.
The good thing about MDF is that it's easy to screw into and for small parts that need profiling some times it's easier because the slots don't line up and make clamping hard if not impossible. Thats why the more and closer the slots are together the better really because it gives you more % chance of always dropping on a hole or something to latch onto with clamps or bolts.

Has you probably Know full well Jonathan the bed and imparticular material clamping is an often un-thought about side of building a machine and can be a right pain in the arse. I can honestly say that yes while it was expensive other than the water cooled spindle it's the best upgrade I've made to my machine by far and wished I'd done it 2yrs sooner, makes work holding so much easier and far more accurate/repeatable.

Jonathan
18-12-2011, 04:35 PM
The good thing about MDF is that it's easy to screw into

That's exactly why I'm hesitating. For almost all the parts I make I screw the aluminium down enough for the router to spot/drill the holes then use those holes for screws to clamp it properly and stop things flying when it is cut out. With the aluminium bed it's more difficult since I would clearly have to make the holes align with the slots which isn't always possible... never straightforward is it!

JAZZCNC
18-12-2011, 05:50 PM
Ye I used to think like that but belive me it is far better and you still can use MDF spoil boards for quick or awkward jobs. The only difference is I don't ever have to surface the bed when it's critical to flat and true. I find because of 45mm centres 90% of the time find a suitable hole or pocket. Drilling is the most trouble some for me but I often pocket holes anyway(If not loads holes) so it's not a big deal.

One of the things I will often do when cutting several jobs that all have different needs is mix both MDF, HDPE and my card board spacer trick and use offsets G54, G55 etc.

I have my bed divided up into area's and have spot drilled small registration dot's so I know the 0,0 of each offset. Then I just fasten each particular job down using which ever method best suits the job lining the board up with the ref marks, line the material up with the corner of the board then in CAM/code I always have the part just in from 0,0 stand back and let it rip.
Depending on the jobs and time etc I don't always do it in one large piece of code, sometimes I'll have seperate code for each job just with the different offset coded in. This way I don't lose too much time unclamping re-clamping etc and can set the next job off straight away because I've set up the next offset while the previous job was cutting, just set the Z0 which is a 10 second affair with tool probe and away it goes again. . . It's quite efficeint.
The other good thing about clamping MDF or HDPE boards is because of the accurate and parallel tracks and offsets I can easily remove and replace the board with work still attached. Sometimes I'll do really long jobs that can be 15-20+ hours long so some times don't want to leave the machine on unattended so pick a suitable point to stop the code but then some times find I need the machine for something else in the mean time.!. . . doing it this way I can clear the table for the new job but still be perfectly back in position and carry on at anytime.

Like I say " FOR ME " it really has been a good improvement and worth the investment but everyone has different needs and ways of working.

JAZZCNC
22-12-2011, 09:03 PM
Yo oh oh James any news on progress.? . . .how close to making chips are we.?

Jonathan
22-12-2011, 09:49 PM
Yo oh oh James any news on progress.? . . .how close to making chips are we.?

I'll let him answer this one :wink:

mocha
23-12-2011, 12:17 AM
They must be too busy making chips to answer! :):clap:

edit...
I know I will be! lol

luke11cnc
23-12-2011, 01:37 AM
So sorry for not updating sooner but Im still smiling and It's been a busy day today as I'm trying to get ready for Christmas

Really BIG BIG thank you to Jonathan for wiring up the CNC machine and letting Luke help you solder and strip wires

well the machine is working and cutting well But I do need to screw it down as vibration is clearly a big issue Please let this be a warning to any one thinking about building a CNC a simple table design is not going to cook it.

I will follow up with a video as Luke took one on my Phone and I will also upload some more photo's as soon as I tidy up the garage (still looks like a bomb has hit it)


I have booked Jonathan to give Luke and myself 3 to 4 hrs training on the machine (don't want to break it!!)

any way I'm happy just sit and look at it and reflect on the journey taken with my son

James

mocha
23-12-2011, 02:06 AM
:clap::clap::clap::clap::clap::clap::clap::clap:

:)

luke11cnc
23-12-2011, 12:26 PM
http://www.youtube.com/watch?v=WtnnJ_xbxqs&feature=youtu.be

I did say I would up load our first ever video of Luke's cnc machine

I have to apologise for the video as Luke was in control of my phone.



More photo and a walk around the cnc later as I have to clean the house,garage,wrap Christmas gifts and go food shopping

James

m.marino
23-12-2011, 01:18 PM
Will look forward to future video. Good to see it running and hope thing continue to go well.

Merry Christmas.

Michael

mocha
23-12-2011, 01:31 PM
yep, looking forward to you doing some videos! Don't forget the glamour shot of the finished item too!

Well done, :yahoo:
have a good xmas.

JAZZCNC
23-12-2011, 10:18 PM
Great to see it shake it's stuff finally. . .Well done and happy Xmas. :clap:

luke11cnc
23-12-2011, 11:03 PM
yes shaking it's stuff is about right but it's not quite finished yet

I have bought the bed material and some brackets to screw it down to the floor

I must admit I was shocked to see how much power is in the stepper motors

James

JAZZCNC
24-12-2011, 12:49 AM
I have bought the bed material and some brackets to screw it down to the floor

Put some rubber between brackets and floor it helps deaden the sound. Old inner tube work good.

mocha
24-12-2011, 12:00 PM
Horse mat material might be good stuff too... (unless the camera was stationary and that was the CNC moving?? lol) There are some industrial isolation rubbers around that look very similar to car exhaust mounts... got a friendly Quik-fit anywhere nearby?

JAZZCNC
28-12-2011, 07:50 PM
You can always tell when someone has there CNC machine up and running for the first time.:question: . . . Because you never bloody see or hear from them again for weeks.:smile:

Now you see James why I say make sure you finish everything you planned on doing before turning the machine on.!:rofl:

luke11cnc
28-12-2011, 08:02 PM
Dear Jazz

I'm sorry but sadly that is no the case I've been sent some soft ware and have been trying to install it.

But I'm a old dragon according to my kids when it comes to computers

Now I thought I was quite a whiz but sadly NOT.

Plus one off my kid's came home for Christmas and just out of the blue said "You'r going to be a granddaddy" Fuck he has only just turned 18 and I'm still picking myself up of the floor

As soon as I get the software to work I will be posting some work video's I hope I get it working soon as I have clock plans coming

James

JAZZCNC
28-12-2011, 08:22 PM
Plus one off my kid's came home for Christmas and just out of the blue said "You'r going to be a granddaddy"

Oh great congratulations or would you prefer it to be commiseration's.!! . . . . I'm dreading that day, mines 18 in Feb and I'm hoping the day don't come any year soon.!

Anyway keep us posted on CNC side of things. . :beer:

luke11cnc
04-01-2012, 08:07 PM
Well we are cutting

and to see the smile on Luke's face was priceless I would like to thank everyone that helped and gave advice on this project.

I only hope I can pass on what I've learnt to others

here is a small clip and Photo of Luke's Creeper and the finished item

http://www.youtube.com/watch?v=1VK6vsa0BxQ&feature=youtu.be

51665167

I have a better Video but waiting for cable to arrive from ebay

James and Luke

Web Goblin
04-01-2012, 08:50 PM
Nice work guys. Now get some aluminium on there and get the chips flying.

Ian

luke11cnc
05-01-2012, 12:46 PM
Ian I will try and cut some brackets on Tuesday when Jonathan comes over as he knows what he is doing

Cables have come but not the right ones BUT I have found the original cable now but need to in stall the video card into a computer ??
James

luke11cnc
06-01-2012, 01:11 PM
Woohoo

I've got the video working so here is the Video of Luke cutting his "Creeper"



http://youtu.be/oki6vMQ6-G8

James and a really Happy Luke