User Tag List

Results 1 to 10 of 10
  1. #1
    Regular Member
    Join Date
    Jun 2004
    Location
    London, UK
    Posts
    1,281
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)

    Default Servicing a Crank Lock Out Tensioner

    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. #2
    Regular Member Mark A's Avatar
    Join Date
    Sep 2005
    Location
    St Helens, UK
    Posts
    4,313
    Mentioned
    17 Post(s)
    Tagged
    0 Thread(s)

    Default

    The tension seems to vary particularly when I crank the tensioner quickly or very slowly.
    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. #3
    Regular Member
    Join Date
    Jun 2004
    Location
    London, UK
    Posts
    1,281
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by Mark A View Post
    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.
    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. #4
    Regular Member Mark A's Avatar
    Join Date
    Sep 2005
    Location
    St Helens, UK
    Posts
    4,313
    Mentioned
    17 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by R20190 View Post
    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.
    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. #5
    Regular Member
    Join Date
    Jun 2004
    Location
    London, UK
    Posts
    1,281
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by Mark A View Post
    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.
    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. #6
    Regular Member
    Join Date
    Oct 2010
    Location
    UK
    Posts
    157
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Default

    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. #7
    Regular Member
    Join Date
    Jun 2004
    Location
    London, UK
    Posts
    1,281
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by _Rav_ View Post
    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.
    I like it - thanks! But masking tape might wear out pretty quickly. I'll have a think.

  8. #8
    Regular Member Mark A's Avatar
    Join Date
    Sep 2005
    Location
    St Helens, UK
    Posts
    4,313
    Mentioned
    17 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by R20190 View Post
    I like it - thanks! But masking tape might wear out pretty quickly. I'll have a think.
    How about sandpaper? I've seen Kwun use it when he strung with that piano wire

  9. #9
    Regular Member
    Join Date
    Jun 2004
    Location
    London, UK
    Posts
    1,281
    Mentioned
    10 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by Mark A View Post
    How about sandpaper? I've seen Kwun use it when he strung with that piano wire
    I guess very fine wet & dry sandpaper may work but wouldn't there be a risk of damaging the string?

  10. #10
    Regular Member Mark A's Avatar
    Join Date
    Sep 2005
    Location
    St Helens, UK
    Posts
    4,313
    Mentioned
    17 Post(s)
    Tagged
    0 Thread(s)

    Default

    Quote Originally Posted by R20190 View Post
    I guess very fine wet & dry sandpaper may work but wouldn't there be a risk of damaging the string?
    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.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •