[dudz]

Hi,
that ballscrew is 5mm pitch and therefore very little torque is required to offset the weight of the Z axis/spindle.

For a 5mm pitch screw the mechanical advantage is 125kg (weight or 1250N) for every 1Nm of applied torque. So if your spindle/Z axis weighs 20kg you'll only need
20/125=0.16Nm from your motor to oppose gravity....bugger all. You want much more torque to accelerate the axis rather than hold it up.

I bought all my linear rails/cars and ballscrews from that same company in Korea. Good supplier, recommended.


Craig

Thanks so much !
What size square linear rails would you recommend using 20/05 ballscrews ? . I'm guessing I go big just for extra stability ?
I have been advised in the past to go double ballnut where I can, to limit backlash etc . But with C5 ground screws and nuts I would guess it would be fine eh ?