I understand that if you have a 1 foot diameter drum with a rope raising 1 pound 1 foot high means you need 1 ft/lb of torque to do the job.
I'm planning a work-positioner for a friend who does welding.
What about ROTATING a load on a platter? A 10" dia disk is on a vertical 1" dia shaft (think of an old LP record player!). The vertical shaft (sitting on a trust bearing) will have a large diameter timing belt pulley/belt going to a small diameter pulley on a BLDC motor - controlled by an Arduino. The load sitting on the platter, centered, would be 100 lbs.
We are looking for LOW speed - under 3 rpms... Now - what torque rating would I need for such a job? :astonished:
I'm thinking the torque increase thru the small-to-large pulley should let me use a modest sized motor... Just can't quite get the torque for this 'horizontal' motion.