Author
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Topic: Question Re. Eumig 824 Sonomatic
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frank arnstein
Jedi Master Film Handler
Posts: 534
From: Gold Coast. Australia
Registered: Jan 2005
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posted July 19, 2014 06:32 AM
Hi to the Members, It's time to see if anyone has the correct answer to the Eumig problem and I must say, it is very pleasing to see the many responses from members. All were very good answers although not quite correct. And now......The correct answer is "a faulty reversing clutch". The drive wheel breakage usually happens because the reversing friction-clutch tension has been over tightened by someone. The result of this over-tightening is, a very sharp yank on the film is applied when it's turned from forwards to reverse project. Every time you turn to reverse project, any slack in the film between the top sprocket and the delivery reel is taken up with a hard yank. Eventually the weakest part breaks and that is the plastic sprocket driving wheel. When put into reverse project, the reversing friction clutch should slip initially and then continuously, and in doing so it will prevent the violent tug by the film to the top sprocket thus protecting the attatched plastic sprocket drive wheel. In most cases, the reason some one has tightened up the clutch is because it had started to slip during fast-rewind. Tightening the friction clutch will improve the fast-rewind as it doesn't slip now, and so "the repairer” considers the problem is fixed. The unknown side effect of over-tightening that friction clutch is that it won't slip when it should slip, and that’s when it is turned to reverse project. A clunk is sometimes heard as the slack in the film above the top sprocket is taken up and then the top sprocket is jerked hard around by the film. Often, it will pull the film off the top sprocket teeth and so can’t really project film in reverse any more. So don’t over tighten the reverse friction clutch to improve rewind function. Rather, dismantle the clutch itself and check the cork friction disc is still glued to its backing metal washer. They have a habit of becoming unglued, and then they just spin with the other washers and don’t function as a friction brake. Reglue the cork washer to its metal backing washer and after lubricating the cork face, refit. Adjust the spring tension to provide just enough pull in reverse-project to rewind the film without coming on with a sudden clunk to the top sprocket. That is the conclusion of this instructional rambling. Thank you all for your attendance. Dogtor Frankarnstein
[ July 19, 2014, 07:51 AM: Message edited by: frank arnstein ]
-------------------- At Projector Heaven the Focus is always on Detail.
____ [o:/o]<|=- dogtor@projectorheaven.com.au //``\\ -----------------------------------------------
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