Ball screw Z axis?

Hi guys,

I’m contemplating upgrading the Z axis all-thread lead screw to a ball screw and a SFU1605 ball nut such as this one. I see a couple of impacts to the MPCNC:

  • The distance of the ball screw center from the rigid middle joiners increases
  • Thus, the Z mount tower will have to offset the hole for the Z axis further out
  • The tool mount(s) will have to accomodate the larger flange that the ball nut has
  • A new Z nut holder will have to be designed

Of course, having better files than the STL files (parasolids?) would help getting this exactly right quicker. But do you guys think it’s an effort that might be worth the time?

What is the main purpose of changing all of this? The only real benefit would be to increase the z axis speed, but you could possibly sacrifice resolution (less steps per rev).

Increasing the distance of the tool holders decreases design strength, that is pretty expensive.

When I chose all the parts I did my best to consider cost vs benefit. I haven’t had any issues with the threaded rod, so for me it was an easy choice.

The main purpose is to:

  1. Avoid the issue that the Z-axis clamped nut drops out of its holder
  2. Increase the Z-axis speed
  3. Reduce the gap/backlash

Maybe you are right in that it might not be justifiable considering the negative impacts further offsetting the Z axis might have. Thanks for the feedback.

Anyone working on converting the MPCNC to use ball screws on all axis? I ask, just because I happen to have 3ea 16" x .362 ball screws available.