Film-Tech Forum ARCHIVE: Knocking Sound

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Posted by Robert E. Allen (Member # 1351) on 01-11-2014, 02:21 PM:

One of my Simplex 35s has developed a sound that, if it were in my car's engine, I could only describe as a knock. The machine seems to have plenty of oil as it splashes on the glass. Do I need to worry?

Bob

Posted by Gordon McLeod (Member # 33) on 01-11-2014, 02:31 PM:

Possibly end play on the shutter

Posted by Matthew Ortado (Member # 5620) on 01-11-2014, 05:19 PM:

Check to see if the fastening screws on the intermittent flywheel are tight.

Posted by Manny Knowles (Member # 1171) on 01-11-2014, 06:32 PM:

A frozen bearing could wear a groove into a shaft. That makes it possible for the affected shaft to wobble around inside the hole, instead of rotating smoothly. This was a cause of knocking for some of my first machines.

Posted by Frank Bolkovac (Member # 6201) on 03-16-2014, 10:37 PM:

Check for excessive end-play on the intermittant flywheel.

Posted by Mark Gulbrandsen (Member # 72) on 03-17-2014, 04:03 PM:

Could it be someone knocking on the booth door? Seriously... You are having so many problems lately I'm thinking digital is a better alternative for you.

Knocking can also be caused by a vertical shaft that has come loose at the bottom bearing retainer. The possibilities here are almost endless...

Getting back to should you worry or not... What's your conversion to digital time frame? If that's happening soon then don't worry. If that's not any time soon then start worrying in a week or two or if the knock gets louder.

Mark

Posted by Robert E. Allen (Member # 1351) on 03-17-2014, 06:38 PM:

It turned out to be the top roller without film. I can hold it with my hand and there's no knock. As for digital it may take me to the end of the year. I'm already feeling the lack of film prints problem.

Posted by Peter Howard (Member # 3491) on 03-19-2014, 09:19 AM:

Slightly OT, but can you still get 35mm trailers on all titles, Robert?