MarkT:
If accuracy is not important, why use expensive ballscrews? Ballscrews have very little friction so if motor power fails the load will fall uncontrolled. Singly-threaded trapezoidal leadscrew ought to avoid that danger, although require more angular velocity for a given linear speed.Some sort of leadscrew is probably good for this high load and low speed requirements.
Three rather than four leadscrews might be enough, saving cost.
I just updated the post. I can tolerate 1mm of inaccuracy.
regarding the cost, its about 60% (a complete z access set) - but it might require a faster/stronger motor, which will cost as much. am I right?
MarkT:
Using one motor and a belt to distribute drive to each leadscrew is also a possibility, again saving hardware,
but the torque requirements might be an issue depending on the pitch of the leadscrew.Simple DC gear motor with encoder is a possible alternative to stepper(s).
Can you recommend on a belt/DC motor?
Thanks!