8mm Forum: Sankyo 700 Speed Control Issue

This is topic Sankyo 700 Speed Control Issue in forum 8mm Forum at 8mm Forum.

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Posted by Douglas Warren (Member # 1047) on November 30, 2016, 08:40 AM:

I recently got (as a gift from my wife) a Sankyo Sound 700 Super-8 Projector. The issue I'm having is that it will run at normal speed (24 fps) for the first couple of minutes then start to slow down to a crawl. Could this be an issue with the speed control circuit? The motor seems strong and the belts in good condition, though the main belt between the pulleys might be a bit slack. Any thoughts,suggestions welcomed.

Posted by Phil Murat (Member # 5148) on November 30, 2016, 09:11 AM:

Hi Douglas,

Here is what I suggest :

- Projector not powered, Hand rotate main shaft, it has to turn freely......(as necessary, put some drops of light oil on bearings or bushings, observe any changes)
Take this oppornuty to glance motors connectors (for loosen wires, conectors, etc....)

- Projector powered, monitor DC voltage on motor (Set multimeter for 50 V range approx)
Observe voltage for fluctuations when projector runs and record when slowing down.....

Let us know

Phil

Posted by Douglas Warren (Member # 1047) on November 30, 2016, 09:58 AM:

Thank you for the advice Phil and I'll give your suggestions a try.

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