Film-Tech Forum ARCHIVE: Bizzare Random Upper Reel Problem

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Topic: Bizzare Random Upper Reel Problem

Gavin Lewarne
Master Film Handler

Posts: 278
From: Plymouth, UK
Registered: Aug 2009

posted 09-02-2009 04:06 AM

i had something similar to this on one of my westars, turned out the gear driving the upper sprocket had a slightly worn tooth, which caused it to slip a tooth when the sprocket was under tension. this caused my upper loop to slowly loose length and cause the problems you describe. i too spent ages altering my clucth tension before i noticed the real cause.

just my 2c

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 09-02-2009 05:57 AM

Actually...I've seen that one too! I want to say the phenolic gear was slipping on its hub.

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Martin McCaffery
Film God

Posts: 2481
From: Montgomery, AL
Registered: Jun 99

posted 09-02-2009 09:49 AM

I've seen gear hub slippage before elsewhere on the machine and it is not pretty.

I've checked all sprockets and gears and have not found anything obvious.

I've backed off the clutch tension to almost nothing. The other machine, which never has this problem, has much greater tension, even though the tension screw is backed almost completely off to spindle. Both are Kelmar arms. but they are slightly different designs. Both have felt pads. Previous recommendation in different thread (from Brad?) was not to lubricate them.

As far as reels, we have what we have. They've worked well 99% of the time. If I could pin the blame on them, I'd change them out.

It is the random nature of this that is so annoying. I can't replicate it, so I don't know if I'm making progress.

Oh well.

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Dave Macaulay
Film God

Posts: 2321
From: Toronto, Canada
Registered: Apr 2001

posted 09-02-2009 10:58 AM

Check the pad roller again, I think. Make sure the spacing is right, dragging a bit on two thicknesses of film and free on one. Check the alignment of the reel and film cleaner, if the film enters the sprocket oddly it can climb up and skip a hole. The reel and film cleaner must be exactly aligned to let the film lie on the sprocket straight and level.

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Bill Enos
Film God

Posts: 2081
From: Richmond, Virginia, USA
Registered: Apr 2000

posted 09-02-2009 01:28 PM

After reading this is just tried about 1/2 inch of film on a 2k aluminum house reel, it takes a good bit of drag to loose the loop.

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Martin McCaffery
Film God

Posts: 2481
From: Montgomery, AL
Registered: Jun 99

posted 09-02-2009 03:35 PM

Checked the cleaner alignment it is ok, but does have a little more play than the other machine.

Checked the pad rollers and reset the second one. The knurled screw on handle was flush against the plastic roller causing extra drag. Didn't freeze it, but did drag it.

We'll see if the problem shows up again.

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