I'm in the planning stages of upgrading my Shopbot CNC router, which will include a new Z axis with ball screw/stepper motor.

How many MM per revolution should I consider for the Z axis ball screw?

I cut lots of 2D profile cuts, but I also need to be able to do sign work and some moldmaking. So resolution is important, but not critical like a lathe or mill might be.

Thanks for the input!

Wayne from White Salmon

As long as your motor has enough power, I'd say around 10mm, which should give you good speed and still have decent resolution.