Mamiya 645 Pro TL - Irregular frame rate with Power Drive WG401

Discussion in 'Medium Format Cameras and Accessories' started by rakeyohn, Jan 4, 2013.

  1. rakeyohn

    rakeyohn Member

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    Hello,

    I recently acquired a Mamiya 645 Pro TL with the WG401 winder grip.

    I have noticed that the "winding sound" is inconsistent. Approximately 3 in 10 advances will sound short in duration, as if the film didn't wind completely to the next frame. Consequently, the frame rate is noticeably irregular when in continuous mode. And this is without film loaded.

    My concern is that the frame spacing will be uneven, but I haven't run a test roll yet.

    I've tried changing batteries.

    Also, there is a pin on the back of the body, top right corner next to the shutter.

    http://youtu.be/D2W301xUBSY In this video (skip to 3:43) the pin pops out and then quickly retracts after each exposure. But with my camera, the pin does not retract half of the time. Should I be worried about this? Could this be related to the frame rate problem?

    One more question: Is it normal for the winding action with the hand crank to feel like I'm breaking something? After 3 quarters of a turn there is a CRACK sound and some resistance and then no resistance at all for the rest of the action. With the Hasselblad the movement is smooth throughout, with constant resistance.

    Any information would be greatly appreciated - I don't know too much about the Mamiyas.

    Thank you!
     
    Last edited by a moderator: Jan 4, 2013
  2. rakeyohn

    rakeyohn Member

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    [​IMG]

    This is the pin that I'm talking about. Ignore the holes in the shutter, just something else to be fixed :tongue:
     
  3. tkamiya

    tkamiya Member

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    Yes - that is normal. What happens is, at about that many turns, the part that film attaches (by tape) to the backing paper rolls over the edge, hence the resistance and the sound. Once that's over the roller, it's smooth as you say.
     
  4. MattKing

    MattKing Subscriber

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    Different parts of the winding procedure do different things - wind the film, cock the shutter, etc.
     
  5. jvo

    jvo Subscriber

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    i have a pro tl and 402 winder - there is a consistent length and sounds when it winds. with the crank it does seem like something's being forced, not difficult or rough, just not smooth and easy - works fine though.

    can't imagine why the winder would vary, but i'd run a roll of film and see.. maybe an expired roll, just to test the winder.

    jvo
     
  6. snederhiser

    snederhiser Member

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    Hello;
    You have to fool the camera in thinking that there is a roll of film in it. Two ways of doing this is to load up a spool with just the backing paper rolled on. Then load the insert with the fake roll of film. Or take about three inches of masking tape and apply to one side of the spool. Then load into film insert feed side making sure the distance roller is riding on the masking tape. Load into the removeable back and attach to camera and see how it works. Steven.