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Tuning machine screw issue

Discussion in 'Setup & Repair [DB]' started by Chansey, Apr 8, 2015.


  1. Chansey

    Chansey

    Nov 25, 2007
    Hi!

    I just discovered that one of the four screws holding my A string tuning machine against the scroll can't be tightened or loosened. It just somewhat spins easily in the hole, but is still holding fast (doesn't drop out by itself). So far, it doesn't seem to be a problem as the tuning machine is still secured against the scroll and the bass still tunes smoothly.

    Any idea what's going on? Are the screw threads or maybe the screw hole stripped perhaps? Is this something I should be worried about? Any potential remedies would be appreciated as well. If it's any help, these are indeed some pretty well aged tuners on a rather old bass.

    Thank you so much for any help!
     
  2. Rocky

    Rocky Banned

    Jul 21, 2000
    Los Angeles
    I had the same problem awhile ago. My solution was to remove the screws, and fill the holes with broken pieces of toothpick then replaced the screw.. Problem solved
     
    SteveCS likes this.
  3. A bodgy easy fix-it is to take the screw out and insert a match stick or toothpick in the hole (break or cut it flush with the surface) and then screw the screw back in.

    edit: Doh, beat to the punch by Rocky........ do what he said;)
     
    SteveCS likes this.
  4. Chansey

    Chansey

    Nov 25, 2007
    As a follow up to the thread, I removed the screw only to discover to my horror that the "looseness" was not due to a stripped hole, but due to the screw breaking clean near the top of the shaft. As I was not skilled with woodwork, I decided to just fill up the hole with some blu-tak/crushed matchstick so that I could replace the broken screw head in the hole and prevent it from dropping out during transportation etc.

    Currently, the tuning machine is still held fast against the scroll by the remaining 3 tuning machines, and there are no rattling issues. While I intend to get it looked at by a professional luthier down the road, I predict repairs will be expensive and may need some surgery on the scroll to remove the broken screw.

    Is it safe however to just leave things be for the time being or is this something that I should get looked at ASAP to prevent any structural issues?
     
  5. Rocky

    Rocky Banned

    Jul 21, 2000
    Los Angeles
    I don't think it would be a problem to wait as long as it doesn't buzz badly.
     
  6. robobass

    robobass

    Aug 1, 2005
    Cologne, Germany
    Private Inventor - Bass Capos
    What kind of bass is it? If it's a CCB chances are that the screws are crap. Might want to replace them all before another one breaks. Removing the broken one isn't a huge deal. Your luthier will have to dig out enough wood to get purchase on the remaining shaft and then plug it with fresh wood.
     
  7. You shouldn't even have to go that far. Auto shops sell bolt-retrieval kits that I've used successfully when I've leaned on a stubborn bolt a little too hard and sheared the head off. No clue if they come that small, but it's worth a look.
     
  8. robobass

    robobass

    Aug 1, 2005
    Cologne, Germany
    Private Inventor - Bass Capos
    No, they come that small.
    Edit - I mean, they DON'T come that small!!!
     
    Last edited: Apr 11, 2015
  9. misterbadger

    misterbadger Supporting Member

    Sep 13, 2012
    Northern California
  10. robobass

    robobass

    Aug 1, 2005
    Cologne, Germany
    Private Inventor - Bass Capos
    That looks like just the ticket. Then you've got a nice clean hole to plug. The mechanics' screw extractors involve drilling a hole into the broken shaft and working in a tapered reverse thread. Even if there were extractors that small, drilling the hole would be almost impossible.

    2nd Edit - OKAY! I looked it up and see that there are spiral extractors as small as 5/64". Still, I don't see how you would ever drill a hole in the center of a broken screw shaft on the scroll of a bass. Maybe a dentist could do it.
     
    Last edited: Apr 11, 2015
  11. Don Kasper

    Don Kasper Supporting Member

    "Does 'that' have an appointment?"
     
    Last edited: Apr 11, 2015
  12. robobass

    robobass

    Aug 1, 2005
    Cologne, Germany
    Private Inventor - Bass Capos
    I didn't remember that Bill Murray was in that film. Funny, we were actually planning to watch Little Shop tonight. Had it all cued up, but then it got too late.
     
  13. Don Kasper

    Don Kasper Supporting Member

    In case it's not been mentioned - when installing small wood screws into hardwood, (especially), it's a good idea to drill a pilot hole of the correct depth and diameter, AND lubricate the screw threads before installation - I've used a bar of soap or liquid dish soap. (The "pros" around here will probably have recommendations, as well).
    Thanks,
     
  14. misterbadger

    misterbadger Supporting Member

    Sep 13, 2012
    Northern California
    Tapered drill bits. Just the ticket. Candle wax or soap helps, especially in maple, which seems to have a natural aversion to brass screws.
     
    Don Kasper likes this.

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