8mm Forum: Help with Magnon take up?

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Posted by Martin Jones (Member # 1163) on July 08, 2011, 03:46 AM:

My Magnon Super IQ performs beautifully except for a strange behaviour of the Take Up spindle.
It's fine during Forward Play, but when it is changed to Reverse or Rewind (in these modes the reel turns anticlockwise due to the pull of the film) the take up reel appears to be too free... i.e there does not appear to be enough resistance or clockwise torque... and the reel overruns causing the film to spill off the spool.

Internally, the feed and take up spindles are linked by a spring belt with a strange "double crossover" path. There are no mechanical alterations effected by the "Forward/Reverse" knob... this function is purely electrical. I cannot fathom what the lack of backwards torque, or resistance is due to.

Anyone any clues?

Martin.

Posted by Pasquale DAlessio (Member # 2052) on July 08, 2011, 05:06 AM:

What about belt tension?

Posted by Martin Jones (Member # 1163) on July 09, 2011, 04:49 AM:

Thank you, Pasquale. Tried that, both increasing and decreasing, with no effect!
This is the machine....

http://www.super8data.com/database/projectors_list/projectors_image_2/prinz_magnon_super-iq.jpg

The shaft goes into a pulley on the inside which contains an interesting "one way drive" consisting of a sliding pin in the shaft engaging with a moulded "cam" recess in the pulley. When the spring drive reverses, there is no direct drive to the take up spindle... but residual stiction tends to turn the spindle anyway. I feel there should be some kind if "friction washer" between the flange of the take up spool hub and the body, but there is no sign of one, and as the machine has clearly had little use I can't imagine that one has worn away.
Anyone with the same machine?

Martin.

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