[Gary Dillard]

We planned to use the FP motor with it's gearbox and a rack-and-pinion for our vertical lift, and knowing how the FP's do not like to stall (I think they were the original source of "magic smoke" back in the days before CIM's when they were one of the choices for drive train motors) we decided to use constant tension springs available in a wide range from McMaster. We assembled everything that was going to be lifted, weighed it, divided by 2 and ordered 2 springs in that range. No close fits required - the ID of the spring is over an inch so we just stuck a 3/8" bolt through it, attached it to structure and screwed the other end to the arm. Works great - without the motor even installed you can move the arm to any position and it stays there.