I have several “quiet drive” slow motion switch machines by American Limited. They seem to have a problem in that after 6 - 7 throws of the switch the drive screw detaches itself from the rubber coupling. Anybody else experience that problem? Anybody got a solution?
I do not have that particular brand, but this sounds very similar to some we use on the club. We have had this problem with them. There were two causes. The first was that they were driving (pulling in) too far on the “retract” cycle. Before the contacts would shut them off they would be pulling the rubber coupling into the motor and so pushing it further and further off the drive screw. To fix this we lowered the voltage which slowed the drive allowing (forcing) it to stop at the end of the contact.
The second problem was the twisting torque upon each start up of the drive. Lowering the voltage and slowing the drive motor helped mitigate this problem.
We have a third problem but it is due to age. The rubber couplings have become brittle over the years so they no longer grip the motor shaft tightly. The only solution is to replace the rubber coupling. We’ve tried glue and other things to no avail.