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Servicing a Crank Lock Out Tensioner

Discussion in 'Badminton Stringing Techniques & Tools' started by R20190, Dec 4, 2012.

  1. R20190

    R20190 Regular Member

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    Does anyone know how to service a Crank Lock Out Tenioner head?

    I have a Eagnas Smart 808 6-point machine that has gradually started to lose it's consistency. When calibrating the tension with digital scales, I find that one test to another the tension can vary up to 0.5lb now. Sometimes a little more.

    The tension seems to vary particularly when I crank the tensioner quickly or very slowly. I have noticed that the string clamp plates are not holding the string as well as used to too.

    I am wondering if anyone on here knows how I can service the tensioner and hopefully resolve some of the problems I am experiencing?

    Many thanks for any help in advance.

    This is the machine I have:

    http://www.eagnas.com/jpg/sm808a1.jpg
     
  2. Mark A

    Mark A Regular Member

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    This is the nature of the beast with cranks, so it's not a calibration problem. The quicker you pull, the more the string will sag.
     
  3. R20190

    R20190 Regular Member

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    Thanks Mark, I did suspect this and have learnt to be more consistent when pulling. But I can't get my head around why this is.

    Have you tried servicing a crank head and do you know how to make the gripper grip better? I've tried cleaning the plates but it seems it may be that the ball-bearings are shifting to one end and so the grip force is not as even.
     
  4. Mark A

    Mark A Regular Member

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    I assume you've wound the limiter screw (back of the gripper plates, has a spring around it) all the way out. Failing this, there's not a lot to be serviced as far as the gripper plates go:).

    You could always take them apart and clean the faces with a toothbrush and rubbing alcohol - sometimes gunk can build up and impede grip.
     
  5. R20190

    R20190 Regular Member

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    Yeah I've done this already. In fact I had to wind that screw all the way out from day one. So it's pretty useless unless I string tennis/squash racquets. There ought to be more adjustment.

    I thought there may be parts that need periodic tightening etc. No probs, thanks anyway!
     
  6. _Rav_

    _Rav_ Regular Member

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    You could try putting some tape with a reasonably abrasive surface (think masking tape rather than electrical, for example) on the gripper plates to give a little more traction.
     
  7. R20190

    R20190 Regular Member

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    I like it - thanks! But masking tape might wear out pretty quickly. I'll have a think.
     
  8. Mark A

    Mark A Regular Member

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    How about sandpaper? I've seen Kwun use it when he strung with that piano wire:)
     
  9. R20190

    R20190 Regular Member

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    I guess very fine wet & dry sandpaper may work but wouldn't there be a risk of damaging the string?
     
  10. Mark A

    Mark A Regular Member

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    If you compare it with how rough the gripper plates are, you should be absolutely fine:).

    An alternative is a folded business card, but the string will "scorch" a groove in it after a while and it will need changing.
     

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