Elevator Design - Rack and Pinion Cascaded - 772

[billbo911]

Originally Posted by Madison

I would avoid using a rack and pinion in this manner because I am not absolutely confident that we could keep both motors synchronized well enough to avoid binding. One motor spinning at a slightly different speed than the other will eventually cause its side of the elevator to be one or more rack teeth off and the elevator may eventually bind.

Madison is absolutely correct on this point!

The workaround should be fairly simple.
Assuming the carriage will carry some sort of manipulator on the front side, move the drive mechanism to the rear. Tie both drives together with an axle. This will keep both motors/pinions synchronized. Just make sure you can adjust the vertical position of one rack so any misalignment of either pinion can be taken into account.

The question I immediately had when looking at your design was: "How do you plan on holding the lift in any position. Do you have a locking mechanism? Or, were you planning on stalling the motors? If stalling the motors is your plan, you really need this thing counter balanced properly.