Cold bending 1 piece cranks?

Discussion in 'Motorized Bicycle General Discussion' started by wayne z, Dec 20, 2011.

  1. maniac57

    maniac57 Old, Fat, and still faster than you

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    Impressive fab skillz there dude! Using whats available is good old-fashioned 'merican ingenuity!usflg
     
  2. Dan

    Dan Staff
    Staff Member

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    Brilliant Wayne! Gonna make one. Thanks, big time.

    Side note. Years back was reading this excerpt from a WWII Vet. He was asked "How did you do it?" He replied; "Didn't know we couldn't. So just went ahead and did it"

    Is one of my favorite mantras in life.

    .flg.
     
  3. atombikes

    atombikes New Member

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    Nice result.

    You mention using "low heat" in a prior attempt. What was the heat source? Propane torch? MAPP gas torch? Oxy-Acetylene torch? Also, what kind of tip on the torch?

    If using heat, shouldn't I just be able to slip a pipe over the crankarm and bend to desired angle (no jig required)?
     
  4. wayne z

    wayne z New Member

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    I used an aceteleyne torch with a #2 tip. This puts out enough heat to quickly get it to a dull red for bending. A propane or mapp will take much longer and the BB will have time to absorb more heat, but might work if you remove the crank from the bike.
     
  5. dracothered

    dracothered New Member

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    I think if you have a Mapp gas with Oxygen it will heat as fast as the acetylene.
     
  6. wayne z

    wayne z New Member

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    Yes that's right. I was referring to mapp only or propane only. Propane with oxy works too.
     
  7. wayne z

    wayne z New Member

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    Yes, when I used heat, I used just a pipe to bend with.
     

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