Rotating Ballnut - design ideas

[Jonathan]

2) Optional
3) Note that on the drawing I posted the motor mount is 88mm wide, not 90mm which is the height of the main block. I intentionally left a 1mm gap so that when the block is bolted to a flat surface, you wont end up with the assembly partially resting on the motor mount (if the motor mount isn't attached accurately). The gap is on both sides since I put mounting holes on both sides of one block so they can be mirrored.
4) Very carefully. You use a 4-jaw chuck and a dial indicator.
7) Same, that's fine.
10) Or CNC4you if you want a cheaper option.

Minor point - on your drawing the 6 tapped holes that fasten the ballnut to the mount go all the way through the flange on the shaft. I made them blind holes so if you accidently try to use too long a bolt, the bolt doesn't go all the way through and damage the bearing.

[Boyan Silyavski]

3) Note that on the drawing I posted the motor mount is 88mm wide, not 90mm which is the height of the main block. I intentionally left a 1mm gap so that when the block is bolted to a flat surface, you wont end up with the assembly partially resting on the motor mount (if the motor mount isn't attached accurately). The gap is on both sides since I put mounting holes on both sides of one block so they can be mirrored.

I see, will correct it.

There are 2 minor changes from the original design:

- i made the motor mount from the wider side, as many will like maybe 34 nema and it looks more sturdy. I wanted to make a combined nema 23 and 34 mount, but i feel sleepy now. when ready will see if it will stay like this or follow your original design.

-i believe i shortened the rotating shaft by making its wide part go through the motor mount plate. It is now 2mm to place the ball screw nut in its place,10mm for the ball screw nut holding thread, 2mm ring to push only the small bearing ring and 90mm the rest.

I think that all can be further shortened and lightened :
-2mm protruding thread instead of 5mm , when the nuts are tightened
-6mm /shortening the whole assembly/ eating from the clearance near the shaft pulley
-The area where the ball screw nut fastens could be recessed 8mm with diameter 40mm and some more holes could be done / 45 degree following the pattern/

This could lower considerably rotating mass