8mm Forum: Chinon 7500 issue

This is topic Chinon 7500 issue - any ideas? in forum 8mm Forum at 8mm Forum.

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Posted by Gary Huggins (Member # 3948) on September 24, 2013, 09:43 PM:

I have a Chinon 7500 that no longer responds to Forward or Rewind.

The middle wheel (see image) is the problem - it doesn't react when the projector is set to Forward or Rewind.

Once that wheel is moved into place manually, everything else on the projector works fine.

Before I start taking things apart - any suggestions on what is not engaging, and how it can be fixed?

Thanks!

Posted by Gary Huggins (Member # 3948) on October 03, 2013, 10:47 PM:

Bumping this query - any suggestions?

I'm trying to repair this for a good cause - a friend's father has been diagnosed with Alzheimer's and would like to watch his home movies with his family while he still can.

So if anyone can offer guidance, and I can get this projector working again, you'd be making them very happy.

Posted by Jon Byler (Member # 3933) on October 03, 2013, 11:25 PM:

might be an issue with grease getting old and sticky. if I remember correctly from looking in my chinon sp350, that gear moves automatically because of the rotational force of some other gear earlier in the drive train, and doesn't have any levers or actuators that move it. but I haven't any idea why it doesn't move for you. hopefully someone else can help, or you get it sorted some other way.

Posted by frank arnstein (Member # 330) on October 05, 2013, 08:33 AM:

Hi Gary

I agree with Jon's thoughts with regards to this problem.

This same thing has happened to me numerous times on Chinons and its always been a case of hardened grease behind the gear that should move up and down to deliver the drive.

The rotational force from the preceding gear, known as a worm-wheel, is all thats usually required to swing the drive from the take up spindle to the delivery spindle.

So try spraying a small amount of lubricant behind the swinging gear and keep moving it by hand till it frees up again and can swing on its own. If its stubborn, you may need to dismantle it partially to clean and re-lubricate the mechanism.

We all want the show to proceed while there is still time for the elderly gentleman to enjoy it. So good luck with it and let us know how you go.

dogtor frankarnstein

[Smile]

Posted by Maurice Leakey (Member # 916) on October 05, 2013, 09:57 AM:

The grease that we can see looks old and possibly thick. I suggest removing it down to a clean surface and then applying new grease.

It may not be necessary to dismantle unless the moving action cannot be freed.

A drop of oil may help, but if it's a thin oil make sure it does not drip down onto the electrical components. Be sparing because when it's freed it could throw the oil around when the gear revolves.

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