I am working on an electric actuation standard for my company (we make gate valves). I have found a lot of info on the web about Acme power screws, which are what we use in our actuators, but there's one thing I can't seem to find: a discussion about the availability/practicality of using multi-start screws. I am aware of the mathematical relationship between lead, torque, speed, etc, but I wonder whether it makes sense to recommend anything more than, say, a two-start screw. Even though a three- or four-start screw might make sense theoretically, I wonder if such screws are readily available at a decent cost, or if there are other reasons to avoid specifying them. Any insights?A multi-lead screw will necessarily be steeper,and it will progressive lose the self-locking effect. So any thrust against the drive nut will tend to back-drive the actuator. That'll make you need a mechanical brake to keep from overheating the motor. Also your mathematical tools should reflect that the efficiency drops off rapidly. This effect also will cause the motor to work harder for a given distance or force.

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