Film-Tech Forum ARCHIVE: CFS motor/sparks a flyin

This is topic CFS motor/sparks a flyin in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Dominic Espinosa (Member # 2122) on 03-25-2007, 03:51 AM:

This evening between reels (platter at rest, dial at 0 on the MUT) the motor shot off 2 big sparks and pops.
Following this it was dead.

I swapped it out to get us going again but I'm curious what would make it go off like that for no reason with, presumably, no current?

Posted by Monte L Fullmer (Member # 2797) on 03-25-2007, 05:33 PM:

..have you pulled the back off the motor and see what the "poof" was all about?

..bet the diode inside took a dump.

Posted by Jonathan Worthing (Member # 803) on 03-26-2007, 06:16 AM:

As i remember the switch on the back plate of the motor has a
big resistor on it, which if the switch becomes loose can swing in to the motor casing.

If the power is on there is power at this part, So sparks can fly at any time [scream]

Posted by Aaron Sisemore (Member # 145) on 03-26-2007, 06:56 PM:

Resistor is probably broken in half.

I can get you another one. [Smile]

-Aaron