8mm Forum: Keystone 109D Motor issue?

This is topic Keystone 109D Motor issue? in forum 8mm Forum at 8mm Forum.

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Posted by Chris Smart (Member # 7022) on August 26, 2019, 08:44 PM:

Hi everyone, I need some help! My projector has been running fine up until tonight when it started fluctuating in speed. It happened while watching a film, it slowly came to a stop near the end of the reel. I usually run films at half speed and thought it might be caused by a warped reel and the film getting caught on the sides. I turned the dial to a higher speed and it started moving again but now when I run it without film I can hear fluctuations in its speed and if I reduce the speed it sometimes crawls to a stop.

Is this an issue with the motor or does it need to be greased?

Posted by Chris Smart (Member # 7022) on August 27, 2019, 10:12 PM:

Does anyone have experience taking apart these projectors? I'm trying to access the gears connected to the motor.

Thanks

Posted by Nantawat Kittiwarakul (Member # 6050) on August 28, 2019, 05:32 AM:

Not specifically to this projector but...

My general rule in such a case is to isolate the cause first. Is it mechanical or electrical problem? If you can somehow disengage the drive motor from the mechanic that will be much easier.

If the motor runs fine when disengaged, then check for sticky mechanism.
If the motor runs slow even with no load, check the motor itself.

Recently spent a few nights trying to bring back this beast from death (it sometime runs for a few second, then back to death). After nights spent without progress and I'm about to give up. I then noticed gunk/goo INSIDE the drive motor (around the armature). A total disassembly+clean up+lubrication+reassembly, and it's back to life again. [Big Grin]

Posted by Chris Smart (Member # 7022) on August 28, 2019, 06:14 AM:

Thank you Nantawat for the reply! I have hit a snag (literally) while disassembling the casing around the motor. My problem is that I cannot disassemble it for further inspection. I have removed all visible screws that retain the motor and it's housing and shields but it seems to be obstructed in the area of the motor and the belt or gearbox?. Inadequate movement of the loosened covers prevent observing just what is holding it. The loosened cover moves perhaps 1/4 in all directions but no more. I don't want to force it and damage the belt or something else. The motor casing has been misaligned so much now I strongly suspect a full disassembly will have to be completed before I can get it back together.

Posted by Chris Smart (Member # 7022) on August 29, 2019, 07:11 AM:

Can anyone recommend a safe way to remove a belt around a motor safely without damaging it?

I have kept the screw in place on the casing (top of picture) to prevent the weight of the motor from pulling on the belt. I need the belt removed to get access to all the gears.

Thanks!

Posted by Nantawat Kittiwarakul (Member # 6050) on August 29, 2019, 10:38 PM:

Not sure...but if you can somehow "slip" the belt out of the pulley - literally disengaging the motor from the rest of the mechanic, that would be enough for inspection.
With the belt disengaged, can you turn the projector easily with your hand? How does the motor behave without the load?

Posted by Chris Smart (Member # 7022) on September 04, 2019, 09:30 AM:

Thank you Nantawat. I decided to play it safe and bring it to a local camera repair specialist who can also repair projectors. I didn't want to chance damaging the belt.

Thanks for your help!

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