Film-Tech Forum ARCHIVE: motor switch issues

This is topic motor switch issues in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Michael Uebler (Member # 6876) on 08-22-2012, 02:37 PM:

so for two shows now i've had the motor switch give out on me. For example the show will be running and the switch will still be in the on possition, but the projector will start to slow down until i turn it off then on again real quick it'll work like normal again. My first instinct is to just replace the switch but i figured i'd get a few more opinions on the issue before i go ahead and do anything. Any suggestions?

Posted by Randy Stankey (Member # 64) on 08-22-2012, 04:44 PM:

Double check the wiring to the switch and to the motor first. Frayed wires or loose connections can cause problems like this.

Next, check the motor relay. Bad contacts or coils can cause intermittent problems.

I think the switch would be the last to go. Relays, wires and the connections between them would be more likely to have problems, in my opinion.

In many cases, it's easier to pop a relay out of its socket and replace it than to replace a switch anyway.

Check the easy things first.

Posted by Michael Uebler (Member # 6876) on 08-22-2012, 04:57 PM:

thank you randy i'll do exactly those things before i jump the gun and order new parts or something i'll take a look soon and post back

Posted by Jim Cassedy (Member # 4115) on 08-22-2012, 05:06 PM:

A little more info would be helpful in diagnosing the problem.
Does the switch control the motor directly, or through a relay?
I agree with Randy that loose connections are one good thing to
check first.

If this is an older set-up, which has one of those old double or single pole 'snap' type switches mounted directly on the motor or projector pedistal, than it's good to check all the
screw connections on it, and then the switch itself.

I've seen these older switches, some of which are 30-49 years old just plain wear out or become 'jiggy' from years of use.
In fact, I had one fail earlier this summer, giving the same symptoms you describe.

If this is a newer installation where the switch controls the motor through a relay, you might want to try cleaning the relay contacts, and if it's a plug-in type relay, clean the relay. socket & plug contacts too.

Posted by Michael Uebler (Member # 6876) on 09-01-2012, 09:12 AM:

so ya after reading everyones advice before i even go to cleaning the equipment i realized that on my simplex super base theres the exact same switch on the other side that was once used to manually change over sound so i cleaned things up (turns out there was no relay) and changed out the switches, no problems since. Thanks again everyone