Film-Tech Forum ARCHIVE: Limit Switch on Tom Thumb Masking Motor

This is topic Limit Switch on Tom Thumb Masking Motor in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Bernie Anderson Jr (Member # 410) on 10-19-2008, 11:08 AM:

I'm using a tom thumb masking motor from ADC and every now and then, the little plstic arms that trigger the limit switches decide to move resetting the points. It seems when the arm hits the switch the shaft spins in the arm's opening keeping the arm from moving. Each consecutive time it travels, it moves. Is there a way to lock down these arms to keep them in position?

Thanks Bernie

Posted by Gordon McLeod (Member # 33) on 10-19-2008, 10:38 PM:

Some vintages had a Jam nut on either side of the arms to supply tension if not then the plastic arms are worn and need replacement