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I got the new arrowhead Golden Age A-style tuners to replace the worn out original tuners on my 1925 Gibson A-jr mandolin. I was hoping they would be a "bolt-on" replacement but it looks like I will need to do some more work to get these to fit (isn't it always more work?:))? Although I'm not a complete newbie I am still a beginner at lutherie and repair so I thought I would get some opinions from you guys on the OLF forum on how to proceed.

I have two issues I must deal with. First, the original screw holes do not line up exactly, although they are close. What is the best way to plug the original screw holes? I was thinking of filling them with epoxy glue?

Second, the tuner bushings on the new replacement tuners are slightly larger than the original tuner bushings and they will not fit in the tuner holes. The original bushings are too small to use on the new tuners. My only option is to drill out the tuner holes slightly larger. What's the proper way to do this? All I can think of is hold the neck in a vice and have a sharp drill bit and a steady hand with a power drill.

I attached some pics (if they uploaded correctly). This is a relatively expensive instrument and I am very fond of it so I don't want to screw it up. Thanks for any advice.

Goodin.

Well, if it were mine I would stop in my tracks and look further for tuners that retrofit directly. I'm not sure about the value of an instrument like that, but...I'm quite curious as to what others will say.

IMO,
Don't drill or fill anything on that instrument.

It's 86 years old, and a Gibson.

Can't you rebuild the original tuners?
I regret doing work like that on an instrument from the 60's.

If I was doing this tuner replacement I would fill the holes with a small dowel or maybe a round toothpick and LMI or Titebond glue. Then I would use a StewMac or LMI peghead reamer to expand the bushing holes.

_________________
Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

Meddlingfool - It's appraised value is $2500. As far as I know these tuners are the closest to a direct retrofit available, except for the bushings being slightly too large and the screw holes not being perfectly aligned of course.

Alan - I had a luthier friend try to refresh the tuners but it didn't help. I think he just lubed them up a bit though. Is there a procedure to rebuild tuners? I'm not overly concerned about doing this tuner replacement on this mandolin since I had the fretboard replaced due to the originally mis-aligned frets; it is not completely original. It's my main gigging axe (or hatchet would be more appropriate), and I would rather have it playable and tunable than original.

Ken - Like this? - http://www.stewmac.com/shop/Tuners/Tune ... amers.html

Yes.

_________________
Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

You may want to consider these bushing reamers instead.

http://www.stewmac.com/shop/Tools/Drill_bits/Peghead_Bushing_Reamers.html

_________________
Michael Lloyd

“I was born to ignorance, yes, and lesser poverties ...
I was born to privilege that I did not see ... I didn’t know it, but my way was paved” – John Gorka

You might want to turn the posts down slightly so they fit through the original bushings. I wouldn't think you would have to remove much material to make this work.
If you don't have a lathe you could chuck them up in a drill press and use a file.

I think Michael is right. Those would probably be better.

_________________
Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

Thanks Michael. I think I will try the bushing reamers instead, which would be much cheaper than the peghead reamer. Now I need a good vise to hold the neck while I drill. Any suggestions? I'm leaning towards the StewMac vise but hope to find something cheaper, or perhaps made in USA. Thanks.

Clay, that seems like way more work and more of a learning curve than I want to tackle right now!

Howdy Gil,
StewMac sells http://www.stewmac.com/shop/Tuners/Tuner_parts/1920s-style_Tuner_Bushings.html?tab=Details#details these bushings which look similar to your old ones. The shaft diam. is .255 and the OD is .283. One thing to note is that the bottom of the shaft "returns" or curls in making the diameter slightly smaller at that point. Have you tried turning your old bushings upside down and seeing if they fit over the shaft that way - just to test the basic shaft diameter?

Good luck, benny

Hi Benny - Comparing the specs with the vintage replica bushings and the bushings that come with the Golden Age tuners, I think it will work. Thanks for the tip. I'm glad you chimed in before I started reaming. I'll try turning the original bushings upside down and see if they fit, and also measure them. Ill let ya know how it goes. Gil