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Seems like it'd be easier just to use two angular contact bearings in the traditional setup? Don't need to be expensive ones.Quote:
Originally Posted by Steel
But yeah, that'd do the job well enough. Much better plan than hanging it all off the stepper shaft.
I Just had a idea !!! thanks Routercnc !!!
Excellent! Even if not perfect, it will greatly reduce the strain on the steppers and your accuracy will be miles better than the originally planned solution would give you and is pretty similar to what I did in my first build.Quote:
Originally Posted by Steel
I used these 12mm pillow block bearings on X and Y:
Attachment 20990
I had one on each end of the screw and they definitely worked well for me to make pretty small things very accurately until I decided to upgrade.
Just a little bearing info chart, I have decided on a 3200 double row angular contact bearing 10x30x14 at the drive end and a 6000z at the other end
Attachment 20995
Only downside really of the double row AC approach is that you can't preload to remove any play like you can with two separate AC bearings back to back.
Will still be more than sufficient for this machine though, and far far better than the first design. Glad you are adding separate bearings.
Ahh i didnt think of that !!Quote:
Originally Posted by Zeeflyboy
If that double row option is easier and cheaper for you then I wouldn't sweat it too much... The backlash from it will be fairly minimal and not going to be the limiting factor on this machine - It's still a big improvement over your original plan.
Today had a hour free to make a quick holder to test the thrust bearings i have, made a few mistakes but im kinda on track, there was a radial bearing that fits in the holder between the two thrust bearings but the bearing i was going to use was only 8mm ID no good as the shaft has a 10mm thread on the end lol
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If you have fitted thrust bearings either end and a ball/deep groove bearing in the middle then that will work OK. If you only have the thrust bearings then your coupling (assuming you are using one between shaft and stepper) will not like the radial loads.
The cost of the proper (e.g. BK12/FK12) parts is not too bad (~£22 for angular contact bearing block set at stepper end and floating bearing set at other end):
https://www.aliexpress.com/store/pro...612.0.0.xrHjqj
Attachment 21017
This price is if bought separately. If bought with the ballscrew and nut as a complete kit I think this would end up much cheaper.
I just found a 10x22x6 so yes thrust radial thrust
No wait i brought a 10x30x14 double angular bearing so ill just use that, heres a bearing holder i made for that bearing.
Attachment 21021
Made some progress on the build i got the y axis hooked up to the lead screw but that was about it.
Also found all is not what it seems with my BK12 fixed end blocks i brought as part of a kit off ebay
no angular contact bearings here just plain old 6001z's
Attachment 21065
After many emails with the ebay seller I was given 6 angular contact bearings for the BK12 blocks,
That should be a lesson for anyone buying BK blocks always ask the seller what bearings there fitted
with before you buy !!
Today i got around to fitting the lead screw for the z axis, i made the bearing holder and fitted it with a
3200-2rs that should take care of any axial load..I have also fitted a nut with grub screw to add preload
I decided to go belt drive so i can mount the stepper and not have it sticking up in the air.
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OK well screw the draw slide idea this is my current build ...
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Much better way to go, just need to do the same on the Z axis now. How you driving the X & Y axis?
Y axis will be driven by 1605 ballscrew and since its a 2 motor x axis ill drive it with 16mm trapezoidal thread since i have a meter spare and, im going try the z axis first before i make any changes see if it holds up to cutting wood. I did the layout like i did because i can make cuts 800 high and 400 wide just in case i wanted to make letters for signs or make one very long sign with this design there's no limit to sign length just height.
Coming along, its been noted before about the bearings being less than what they should be.
If anyone needs some these are really nice: http://www.ebay.co.uk/itm/360612149297
Ignore the pic as what turns up are very nice high quality bearings.