Elevator Design Help

[grem110]

Thanks for all the advice! We will definitely reduce the diameter of the spool. I assume that keeping the worm gear for its anti-backdrive ability is a must? I ran some numbers and discovered that using an RS-775-18 with a 35:1 reduction would work pretty well--I may have forgotten to mention we have a block and tackle pulley system that acts as a 2:1 reduction, so the system would have an overall 70:1 reduction.

Also, how does amperage fit into all of this? Not sure how much amperage to give this motor when I still want to have the robot drive and grab the totes (grabber is motor driven).

Thanks so much for everyone's help.