Seems like it'd be easier just to use two angular contact bearings in the traditional setup? Don't need to be expensive ones.
But yeah, that'd do the job well enough. Much better plan than hanging it all off the stepper shaft.
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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.
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.
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
Attachment 21008Attachment 21009Attachment 21010
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