Film-Tech Forum ARCHIVE: Platter Creep

This is topic Platter Creep in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=008422

Posted by Kevin Raisler (Member # 1761) on 12-17-2006, 11:34 PM:

I was wondering if anyone else is having the same problem as follows:
your in the middle of paying out a show. rarely and for some reason the pay out platter begins to run at a level thats so slow it can't keep up. causing the dreaded brain wrap this problem occurs usally when there is atmospheric changes ie humidity or static. I change my micro switches every two years and keep everything spotless. I am using Potts platters with wrap detectors. could this just be the dreaded microswitch anomaly?

Posted by Monte L Fullmer (Member # 2797) on 12-18-2006, 12:29 AM:

I can see it being the microswitch problem if the brain didn't shutting down the platter when the film payout was all caught up to speed - and causing reverse film wrap around the brain.

Check your motor brushes. I bet you got some brushes that are about shot and the copper braided wire core of the center of the brush is wearing into the com of the motor.

Posted by Alex Grueneberg (Member # 2652) on 12-18-2006, 11:24 AM:

I used to have this problem all the time. It turned out it was due to the motor drive assembly and wheel not pressing hard enough against the underside of the platter. As well, worn out tires on the drive wheel and some build up on the platter where the wheel runs.

Just an idea. [Smile]

Posted by Mark Gulbrandsen (Member # 72) on 12-18-2006, 12:27 PM:

Probably a micro that has failed but also change the drive tires when you change the micros.

Mark

Posted by Kevin Raisler (Member # 1761) on 01-14-2007, 10:42 PM:

I should have been more clear on this on my original post. This problem is RARE like once or twice a year. I appreciate all the feedback. I've checked all of the obvious stuff all of my drive tires are in perfect shape platters are free of oil or grease. platters all timed with plenty of pressure on the disks.
I was intrigued about what you had to say Monte I've taken apart some of the motors and noticed that the brushes are worse for wear. What bothers me is how in the hell do you replace the brushes on Potts motors? aren't they just like Strong Motors? they don't lend themselves to an easy change out. also the comms are
grooved.