Results 1 to 10 of 10

Thread: Slot tuners Stiffness Problem

  1. #1
    Registered User mandrian's Avatar
    Join Date
    Feb 2008
    Location
    Scotland
    Posts
    393

    Default Slot tuners Stiffness Problem

    Hi,

    Anyone provide any help for the following problem?

    Got a 1940s French mandolin. The tuners were extremely stiff when the mandolin was tuned up to pitch. Took off the strings and the tuners then turn easily. The holes on the inside of the slots show some signs of wear (see photos), but the tuners themselves (brass?) look to be in good condition.

    Iíll take the tuners off and clean and lubricate everything, but given that they are turning freely when destrung, Iím not sure this is will overcome the problem. Other than clean out the holes in the wood any other suggestions? By the way the stiffness issue was across all tuner keys.

    I want to sort the issue myself as it was just a £175 mandolin to play in the garden and weíre in lockdown and I could not go to a repairman anyway.

    Thanks!

    Click image for larger version. 

Name:	7EFB597E-057C-4A3C-AA3C-C625AB62C5B5.jpg 
Views:	38 
Size:	698.9 KB 
ID:	186215
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	5D785641-0F2A-4AD2-B07E-C29C4A2E1AA3.jpg 
Views:	33 
Size:	472.5 KB 
ID:	186214  

  2. #2
    Confused... or?
    Join Date
    Dec 2008
    Location
    Over the Hudson & thru the woods from NYC
    Posts
    2,403

    Default Re: Slot tuners Stiffness Problem

    Everything you need to know, thanks to the late Cafe member Paul Hostetter. This treatise has saved probably thousands of us from big mistakes:
    http://www.lutherie.net/tuner.maintenance.html
    - Ed

    "Then one day we weren't as young as before
    Our mistakes weren't quite so easy to undo
    But by all those roads, my friend, we've travelled down
    I'm a better man for just the kowin' of you."
    - Ian Tyson

  3. The following members say thank you to EdHanrahan for this post:


  4. #3
    Registered User
    Join Date
    Jun 2005
    Location
    High Peak - UK
    Posts
    2,772

    Default Re: Slot tuners Stiffness Problem

    Unfortunately, I don’t think he deals with slot head tuners. Posts on slot head tuners have more binding opportunities than ordinary ones with string tension causing wear on one side of the inner hole.

  5. #4
    Registered User mandrian's Avatar
    Join Date
    Feb 2008
    Location
    Scotland
    Posts
    393

    Default Re: Slot tuners Stiffness Problem

    Hi,

    Yes, as Ray said it does not really deal with slot head tuners, although obviously the theory is similar. I’ll take the tuners off and give them the Paul Hostetter treatment to make sure there are no issues there. When they are off I’ll look at the post holes on the headstock which is probably where the issue is. Is there anything I can do there other than clean them? Can I lubricate them somehow? They are bare wood with no bushings.

    I don’t really fancy filing the holes and redrilling, that would probably be beyond me! I suppose using light gauge strings would help if the posts are binding on the post holes?

    Thanks again.

  6. #5

    Default Re: Slot tuners Stiffness Problem

    Yes, those tuners look like brass or maybe bronze, but either way, they are more ‘lubricious’ than steel on steel, so that’s good. That is, they may not benefit from adding grease. The big difference with slotted heads is that the actual bearing points of the post can be the outer or the inner holes or both. Before you unstrung it, you would have seen clearance (above - toward the end) and probably both places, as either wear or drilled that way. Since the string pulls the post, and these are “worm over” gears, more clearance means more jamming of the worm against the cog. This also leads to more load and more friction throughout - the tiny brackets that support the worm. So far, just the same as the other style. So, in my inexperienced analysis, it’s important to keep the long lever arm of the post from putting excess tension on the gears, and the best place to fix it is at the inner holes. Now, unless you’re very creative with machinery, re-drilling just the inners, or even both and inserting bushings could be a really big deal - due to the much longer distance you have to align, I’d, again with no experience at all, do the following:
    With the strings off (and by the way, looks like the frets might need some TLC too), grab the post in the slot with, say, needle-nose pliers, and see if what I said makes sense; that is, lift the post clear of the inner hole wall and see if the apparent slop between the worm and cog goes from zero to something you can feel. Then measure, or guess how much distance at the inner hole that represents - may be quite a bit, like 1/16” or more. Then try inserting a little piece of (best, sheet Teflon) in the inner hole on the proper side, or whatever you can find, maybe even cardboard. You don’t need a real bushing or even a complete circle, just the load side. If it works on one, it will work on all of them. Tool kit needed: scissors and pliers. Pay attention also to what’s going on at the outer holes. And, leverage again, winding the string closer to the outboard side reduces the problem. An alternative would be to relocate the tuner mounting screw holes closer to the neck, but that involves some other steps. There’s yet another possible issue I won’t mention that’s a bit more exotic...
    This is just theory: let us know what you find!
    (About lubes: defer to actual luthiers on this, but suggest that so-called high pressure stuff like lithium grease should be appropriate.)

  7. The following members say thank you to Richard500 for this post:


  8. #6
    Registered User mandrian's Avatar
    Join Date
    Feb 2008
    Location
    Scotland
    Posts
    393

    Default Re: Slot tuners Stiffness Problem

    Hi,

    Got the tuners off and will clean overnight. The tuner post holes do not seem too bad in terms of distortion, that is the holes are circular with no great wear. They do however seem comfortably bigger in diameter in comparison with the posts.

    Click image for larger version. 

Name:	0C7716F4-6396-425E-AA49-2A5F2CAF4C40.jpg 
Views:	28 
Size:	419.2 KB 
ID:	186225

    Thanks for all the advice.

    Regards

  9. #7

    Default Re: Slot tuners Stiffness Problem

    I have the same problem with a paddle head bowl back which I've brought back to playable condition (except the tuners).

    My plan is to find some brass tube which is a snug fit over the tuning posts, drill the headstock to that size, and then use a full headstock-width length of the tubing as a bushing.

    I guess you could do the same on a slot head, bushing both the outer and inner bearing surfaces.

  10. The following members say thank you to ProfChris for this post:


  11. #8
    Registered User
    Join Date
    Jan 2009
    Location
    S.W. Wisconsin
    Posts
    5,530

    Default Re: Slot tuners Stiffness Problem

    A thick piece of the plastic that most products are sold in will cut with a scissors, bend to fit the curve, and shim the post. It will last a long time too. I have plastic behind bushing for a mandolin that had smaller bushings with a tuner change. The originals always turned hard, but in another mandolin the don't. Shimming the blushing worked great. In this case it would be better to shim all, or most of the way around. You can find the plastic in various thickness.

    If you are lucky the little old time thin bushings for guitar may fit the hole and you could push them in and recenter you post. These are thin and since your holes are larger than your post these may work.
    THE WORLD IS A BETTER PLACE JUST FOR YOUR SMILE!

  12. The Following 2 Users Say Thank You to pops1 For This Useful Post:


  13. #9
    Registered User mandrian's Avatar
    Join Date
    Feb 2008
    Location
    Scotland
    Posts
    393

    Default Re: Slot tuners Stiffness Problem

    Hi,

    Thanks for all the replies. I cleaned up the tuner components and tried the trick with making a cylindrical insert for the tuner post holes. Only did this for the outer holes as I did not have the dexterity or patience for the inner holes.

    Anyway, it worked. Only two of the tuner keys are marginally stiff now, the rest work fine. By the way, I hate changing strings at the best of times, but a slot head mandolin is a nightmare. The you tubers make it look easy with a guitar, but I found it a tricky job for a mandolin.

    I put on some Martin 10-34’s that were in the packet, but at least 5 years old and the mandolin sounds fine for the garden at least. If I like the instrument in the longer term will probably put some Thomastiks on it. The neck width is 1 inch, which is a lot narrower than a Sobell!

    Anyway, here it is. NickR you might recognise it. Apologies for the upside down images, always happens and can never correct it.



    Regards,
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	EF44CB29-1241-4BB5-A605-0812BE27004A.jpg 
Views:	25 
Size:	1.04 MB 
ID:	186236  
    Last edited by mandrian; May-29-2020 at 9:23am.

  14. #10

    Default Re: Slot tuners Stiffness Problem

    I do a similar thing to ProfChris and pops1.

    If you take the plastic cap from a Bic pen or similar it can be cut into "slices" to make a peghead shim. It is somewhat conical in design, so you can get a couple different sizes. If it is too big you can remove a small piece from the side and it is flexible enough to make an exact fit.

    Also, there is a eBay seller, cbgitty, who sells old school 1/4 inch peghead bushings both in brass and nickel-plated. I have used these for several guitar repairs, but may be too large for some mandolin pegheads. NFI.

  15. The following members say thank you to Jeff Mando for this post:


Posting Permissions

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