8mm Forum: Slipping Eumig Drive Discs

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Posted by Paul Adsett (Member # 25) on February 27, 2016, 03:29 PM:

An almost universal problem on the Eumig 800 series, and to some extent on the 900 series, is slippage of the motor drive ball aginst the forward and reverse rubber faced drive discs. Various solutions have been offered, and tested, with mixed results. Certainly wiping with alcohol, or lightly roughening up the discs with emery cloth, can help. I have tried both of these solutions, but like many pain killers, they offer only temporary relief.
Today I tried something new, which looks promising, but of course only time will tell. I was in an auto parts store and saw a spray can of fluid that is used to remove squeeks and slippage of fan belts. The product is called CRC Belt Conditioner. I though that just possibly this might help with the Eumig disc problem. So I purchased a can for $4.99. Of course just spraying it onto the drive discs is not the way to go, in fat that would guarantee the ruination of a great projector. So, I took the can outside the house and just sprayed enough into the cupped lid of the can so I could soak the tip of a q-tip applicator. Then I wiped this across the surface of the rubber discs a couple of times and let it dry for an hour. One thing I noticed immediately is that the surface of the rubber now looks a nice deep shiny black, like new rubber looks.
Anyway, when I powered up the Eumig 820 I was impressed with how it immediately came up to full speed in both forward and reverse, running like a new machine.
My S938 has been a little slow lately in getting up to full speed, so I gave it the same treatment and got the same great result! So right now it looks that this may be a worthwhile addition to the list of possible fixes for this problem.

Posted by Clinton Hunt (Member # 2072) on February 27, 2016, 03:37 PM:

Well done Paul,there always has to be someone to try new ideas first!
Goes to show that projector motors and running gears are similar to many other types of machines.Trial and error is the way to go in many cases unless it is a failure and a disaster [Smile]

Posted by Janice Glesser (Member # 2758) on February 27, 2016, 05:26 PM:

Good show Paul! This is the kind of out-of-the-box creativity that is going to keep these wonderful machines running a little longer [Smile]

Thanks so much for posting and let us know how it performs as time goes on.

Posted by Pasquale DAlessio (Member # 2052) on February 27, 2016, 05:38 PM:

Paul

Well done. I have been using the same product on belts and rubber rollers for quite a while. But never thought of the disk. You have to think out side of the (projector) box!

PatD

Posted by Dominique De Bast (Member # 3798) on February 27, 2016, 06:29 PM:

Thank you, Paul ! I hope it will be a long term solution.

Posted by Joe Taffis (Member # 4) on February 28, 2016, 01:18 PM:

CRC also makes a good spray electric contact cleaner...

Posted by Barry Fritz (Member # 1865) on February 28, 2016, 06:08 PM:

I have used a rubber rejuvenator product that is used for rollers in printer and copy machines and also for the platens on typewriters. It is a spray also, but I spray it in a jar and brush it on.

Posted by Lee Mannering (Member # 728) on February 29, 2016, 07:22 AM:

Excellent Paul!

It says on the tin use every 3000 miles, any idea how many feet of film that will be? [Big Grin]

Sorry couldn't resist that.

Posted by Paul Adsett (Member # 25) on February 29, 2016, 10:50 AM:

That works out to 15,840,000 ft of film Lee - or 13,200 hrs run time! [Big Grin]

Posted by Bill Phelps (Member # 1431) on February 29, 2016, 10:53 AM:

Looks like one application should do it!

Bill [Smile]

Posted by Osi Osgood (Member # 424) on February 29, 2016, 12:25 PM:

Is that the sound which sounds like a car starting, when you turn on you're projector? I had that problem in short form some years ago, I can't remember exactly what I did to counteract it.

I have a different problem ...

At times, when I turn on my 926 EUMIG, it will start a little slow, rev up to the 24 fps after just a bit, but it can fluctuate back and forth just a little. It seems to be getting worse at this, even if I use it daily. I thought this would have been a problem with a projector sitting idle for weeks.

Posted by Gary Crawford (Member # 67) on March 01, 2016, 06:36 AM:

Paul...I was told about belt dressing sprays for Eumigs back in the 80's when my old Standard 8 Mark S began to slow down. The dressing stuff worked for a while, but eventually the metal ball and hundreds of hours of operation wore an actual indentation in the rubber wheel. For a while I used the cycles switch to move 24fps up on the roller a bit. But again, the wheel wore down and that was that. If someone could come up with a process to re-rubberize the wheel, THEN we'd have something.

Posted by Paul Adsett (Member # 25) on March 01, 2016, 09:58 AM:

Obviously that is the ultimate solution to this problem Gary, Many years ago I did in fact repair an S 709, which belonged to a friend of mine. I had access to a really good machine shop where I worked, and was able to 'bootleg' the manufacture of some special parts for his Eumig at no cost (to me!). These included two new Delrin AF bushings for the motor mount, and two Butyl B612-70 rubber discs'. These discs were 0.062 ins thick, and I cut them across the diameter with a razor blade in one place from the outside diameter to the inside diameter. I then was able to position these on top of the original discs and bond them in place with a thin layer of Scotchweld epoxy. It worked great!

Posted by Steve Klare (Member # 12) on March 01, 2016, 10:23 AM:

I have this idea of putting rubber shrink tube over the metal ball, but until my Eumig grinds to a halt it is no more than just a theory!

I have enough broken stuff to mess around with that I never feel the need to "fix" the functioning stuff!

Posted by Joseph Randall (Member # 4906) on March 01, 2016, 12:31 PM:

quote:
If someone could come up with a process to re-rubberize the wheel, THEN we'd have something.

Phil Johnson did just that -- but he was selling the part for about the price you would pay for a whole projector on eBay.

Posted by John Armer (Member # 4655) on February 12, 2018, 05:09 PM:

Paul, how did you get on with the CRC belt conditioner after more than a years' use? I have a couple of 900 series Eumigs and, while the speed is mostly OK at the moment, one of them occasionally takes a few seconds to speed up when started up from cold. If the conditioner has been OK I'd be interested in getting hold of some of this to keep the machines running in the future.

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