Fixed - Mamiya M645 1000s (and all clones) counter not resetting

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  • Thread starter Deleted member 88956
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Deleted member 88956

While there is already a discussion and solution posted, it might go amiss if one searches for it, so perhaps this targeted thread would be helpful. Multiexposure lever warning is well explained in the manual, just added it here for completeness (and being new to M645 I had to notice

The problem that appears to have been repeatedly reported by users of original Mamiya M645 (J, plain, and 1000s) with counter not resetting to S and if not spotted, leading to partial use of loaded film, or if severe to bigger issues

Basics:

1. Counter should reset itself to S immediately when insert gear disengages from counter gear in the body (meaning it will happen once insert is moved out a mere millimeter or so). If counter does NOT snap right back to S, it is a sign of problem.

2. So two things for loading film into M645 are critical (assuming actual placement of new film onto the insert has been competed correctly). Before insert goes in
  • counter is showing "S" (this must be correct BEFORE insert goes into the body)
  • Multi exposure lever (on the 1000s) is NOT engaged (this can be fixed BEFORE first move of the advance crank, but insert can be already be in the body)
Multi exposure lever is important because film does not advance, only shutter gets cocked in this mode so film would not advance to first frame. So importance rests with the fact that if one does not get things started correctly, he might end up shooting a few frames before realizing the mistake.

Counter is another matter. Fortunately, while possibly not a fix for every single case, it appears to be and it is easy to spot where the problem is.

There is a small metal gear in the body that interacts with gear on insert. The gear on the body ought to be completely free and when rolled by finger should immediately snap back to a stop once finger is off. Essentially as film is advanced a spring is being loaded with moving gear. As long as insert is in the body, spring remains loaded. Once insert is pulled out, that loaded spring brings the gear back to its original stop and counter is back to "S".

If gear is finger moved and then either does not move at all, or kind of moves but erratically, it is NOT how it is supposed to be (I noticed on insert removal the gear was jerking its way back). You can use a finger to walk the gear back so "S" is in position before inserting new film, but it is clearly not a solution, certainly not a long term one. If you have a hard time moving that small gear with finger, then it is more serious and could cause actual damage to gearing set up, if force required exceeds design parameters (gear is mounted on very small shaft and at least mine shows slight side play when touched).

The problem appears to lie in the gumming on the gear shaft that over time inflicts too much friction for the small spring to do its work (this is a low load spring that will not overcome anything, but smallest friction).

Fix is in lubricating the shaft. A very small amount is needed so need to be careful, just keep in mind it needs to go UNDER the gear wheel not on its top. I have made a small baffle from paper that was slide around the back of gear wheel to protect shutter curtain) and then used silicone based light grease to squirt a bit under (I had one supplied in spray can with small tubing for precision pointed application) . Any other light lubricant should work and use a needle or other similar applicator to drop in a tiny bit, then just finger work the gear a few times.

Gear was back to new operating condition withing seconds of this approach and now flies right back in as it should.

In the end, if you have this problem, try this before shelling out on service, which will likely do this first anyways.
 
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R Paul

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Oct 15, 2010
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wonderful ne
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You know what---- It worked !!
Thanks so much , now I can start taking it out for walks again
 
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