My neighbor wants to build a scissors-type motorcycle lift (as seen on the motorcycle-building shows) and has asked me to help him design and fabricate it.
I'm thinking that the simplest and safest way to go is to use a screw to provide the lift rather than a pneumatic or hydraulic cylinder. I see that Enco is selling 1" - 5 TPI ACME threaded rod and nuts, which sounds sturdy enough for a ~1000 lb. load. I'd like to use a reversible motor to crank the screw.
The question is, how do I, even roughly, calculate the minimum "comfortable" horse power required to operate this lift? I'm figuring on using a single scissors with the hinge point at mid-point on the arms, so the ratio will be 1:1. I guess the missing variable is the length of the arms...?
A related question has to do with gear reduction. Will a steering box from an automobile work as a gear reduction unit once the steering arm is removed? Are they designed so that the output shaft will rotate multiple times, or are they limited to only a partial revolution?
Thanks