Tired of Using a Torch to Bend Cranks.

Discussion in 'Motorized Bicycle General Discussion' started by rohmell, May 8, 2011.

  1. rohmell

    rohmell Active Member

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    Yes, I am tired of using a torch to bend the pedal cranks out for clearance for pull-start and centrifugal clutches, so my plan is to use a rewound microwave oven transformer controlled by a variac to heat the crank to bending temperature.
    To give you an idea of what I am talking about:

    YouTube - High Current Microwave Oven Transformer Test

    Of course, the variac will be uses to control the output so that there will be some element of repeatability and safety when using such a technique.
    Anyone ever try such an approach?
     
  2. Dan

    Dan Staff
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    Pretty amazing Rohmell. Please post some vids when ya try it.
     
  3. bairdco

    bairdco a guy who makes cool bikes

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    i use a 6' long pipe and a crack in the cement under my shed. no heat involved.

    wedge the crank under the shed, put the pipe over the other arm, and it bends easy peasy japaneasy.

    i could probably bend the crank into a straight line with enough pressure.

    "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world."

    Archimedes
     
  4. corgi1

    corgi1 New Member

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    Oh please Mr.,don't hurt my screw drivers,They're old and don't work like new,but we all get that way in time and they're all I got,lol
     
  5. 42blue15

    42blue15 New Member

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    It's interesting to look at, but why do you think it will work better than a torch?
    With a torch, you can only heat the spot that you want to bend...
     
  6. rohmell

    rohmell Active Member

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    Depending upon the placement of the two leads from the transformer it will allow localization of the high current heat, similar to using a torch.

    But, before I give this a whirl, I am going to try using a 12 ton press for my next crank bend, and see how that works out.
     

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