Idiot proof tool to enlarge a tuning key hole

[Bruce Johnson]

I dont actually disagree with any of this in general practice but there is an argument for a tapered hole with ultralites because the threaded cap is bigger than the shaft of the tuner. Because of that a hole sized for the cap leaves a fairly large gap around the shaft of the tuner on the back side of the headstock. If your hole isn't perfectly centered and square it gets very close to showing from under the casing of the tuner. When I install them I drill a smaller hole on the back of the headstock sized for the shaft and then a larger hole on the face of the headstock to accommodate the threaded cap.

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An added benefit is that drilling the hole in both the front and back face drastically reduces the chances of tear out. This may or may not be useful in OP's case but its something I put some thought into recently. Reaming from the front with a tapered reamer would leave a smaller diameter hole on the back of the headstock and with the right size reamer might be an easier and more elegant solution than mine.

Yes, what you are showing is the correct hole for a tuner and bushing. A through-hole in the back of one size to fit and support the tuner, and a larger counterbore in the front to fit the bushing.

For a 1/2" post bass tuner, I first drill a 1/8" pilot hole all the way through the headstock. Then I use a 9/16" Forstner bit drilling from the front to about half depth. The point of the Forstner bit will follow the 1/8" hole accurately. Then flip it over, and finish the hole with the Forstner bit from the back side. That makes a neat 9/16" hole straight through.

Then I use my special reamer from the front side. Its front pilot is slightly less than 9/16", and it cuts the 11/16" counterbore, 7/16" deep. And that's it, the hole the tuner was designed for: 9/16" through, with an 11/16" straight-sided counterbore from the front, 7/16" deep. That will fit almost all 1/2" post tuners, whether press-in bushings or threaded bushings (like the Hipshot Ultralite 1/2").

For 3/8" post tuners, the sizes are: a 1/2" hole through, and a 9/16" counterbore, 7/16" deep. That's what it's supposed to be. However, most people just drill 9/16" straight through for 3/8" post tuners.

Most of the mini-tuners work fine in a plain 9/16" hole. And the best way to drill that is with a 9/16" Forstner bit, following a 1/8" pilot hole, as I described above. Drill in from the front and the back.

From the factory, most basses that came with 3/8" post mini-tuners are drilled 9/16" through. Basses with old-style 1/2" post tuners are drilled with the stepped hole of 11/16" x 9/16".

 

[Bruce Johnson]

I can't believe nobody has suggested using a round file to enlarge the hole.

I did, up in post #17! If you don't have the correct drill bit or reamer, a big round file is the simplest, safest way to enlarge the hole.

 

[Aidenn7]

the thing that no one has said you don't want to ream from the center but an offset ream away from the edge.. because you want to have more wood on the outside.. so it's retains the strength and it doesn't run the risk of stress cracks at the hole..

 

[Robscott]

I'm getting the cold sweats just reading about this! OP, please post again to say it all went OK

 

[dwizum]

I can't believe nobody has suggested using a round file to enlarge the hole.

I can't believe you missed the THREE people who suggested using a file before you made that post.

My personal preference for a "I don't have many tools and have no experience with this" approach would be to get a round file, trace the desired hole size on both sides of the headstock, then file the hole until it meets the lines

figure out your specs first then go buy a rat tail file (it's round) and work the holes open gradually.

If you don't have any of those tools, the safest thing is a large round file.

But, hey, this thread just hit the hot topics list on the home page, so I guess we can expect a flood of people who are so eager to listen to themselves type that they don't read first. So I guess you can be forgiven, at least you had a suggestion that was actually good.

 

[Panek]

I bought a bass that has 2x2 Y style tuning keys that are I believe 3/8 in diameter on the headstock. I want to swap them out for some Hipshot Lic Ultralights which I think I need to increase the hole size to either 1/2 or 5/8. I will measure to make sure once it arrives. Is there an idiot proof way to enlarge the holes? I don’t have a drill press - I do have some nice hand drills with forstner bits, etc. But what is the easiest way to do it without potentially jacking up the headstock?

Sorry if this is the wrong place - I wanted to ask the woodworking experts. Thanks!

Back in 2012 I had to do the same thing in my 2009 Fender Precision AmStd for vintage style Kluson-like tuners that I wanted to install. I put some sandpaper around a Sharpie pen, put it in each hole and carefully turned it, slowly removing excess wood. As soon as the new tuner bushing was a nice, snug fit after a couple of turns I put it in.

Yeah, I know this might not be the best "professional" way to do it, but it's been 9 years since, the bass has been on the road plenty, stays in tune perfectly, no cracks have developed in the headstock - and believe me, this axe has seen some... things. So if you're confident enough, ream away!

 

[dbsfgyd1]

I bought a bass that has 2x2 Y style tuning keys that are I believe 3/8 in diameter on the headstock. I want to swap them out for some Hipshot Lic Ultralights which I think I need to increase the hole size to either 1/2 or 5/8. I will measure to make sure once it arrives. Is there an idiot proof way to enlarge the holes? I don’t have a drill press - I do have some nice hand drills with forstner bits, etc. But what is the easiest way to do it without potentially jacking up the headstock?

Sorry if this is the wrong place - I wanted to ask the woodworking experts. Thanks!

One way to idiot proof this project is to keep me away from it. I can do a lot of things, but get me alone with a piece of wood and it will not turn out well.

 

[Dan_reeves]

I'm getting the cold sweats just reading about this! OP, please post again to say it all went OK

LOL - I won't be receiving the bass until Thursday. So this will be a weekend project most likely. Just gathering all suggestions prior to starting the work.

 

[Bruce Johnson]

LOL - I won't be receiving the bass until Thursday. So this will be a weekend project most likely. Just gathering all suggestions prior to starting the work.

By the way, if your new bass has the typical style mini-tuners, then the holes in the headstock are probably already 9/16" through. If you order a set of Hipshot Ultralights with 3/8" posts, their bushings will fit right into a 9/16" hole. That's what they were designed for. No drilling or reaming needed.

If you order the Ultralights with 1/2" posts, then you will need to drill or ream the holes to 11/16" dia x 1/2" deep.

 

[Dan_reeves]

By the way, if your new bass has the typical style mini-tuners, then the holes in the headstock are probably already 9/16" through. If you order a set of Hipshot Ultralights with 3/8" posts, their bushings will fit right into a 9/16" hole. That's what they were designed for. No drilling or reaming needed.

If you order the Ultralights with 1/2" posts, then you will need to drill or ream the holes to 11/16" dia x 1/2" deep.

I already have the Ultralights in hand from a different project that was abandoned. They are the larger size. I am considering using banjo replacement buttons to swap out the ends of the Y keys - if it works, then I can use the stock tuners but still retain that beatle bass look. So that’s another option I am throwing around. Part of it will depend on what the neck dive is like. I was considering the Ultralights because I am assuming there is dive, but I guess I won’t really know that until I get the bass. UPS say Friday now, so I am keeping my fingers crossed. Thanks again!

 

[Dan_reeves]

So, just as a quick follow up. I received the bass on Friday. It plays well, feels good - I am glad I bought it. There are some electronic issues, and the previous owner had sort of messed up the control plate with a weird "mod" - they used what looks like fingernail polish to paint the black switches white (as well as some screws). So I made the decision to purchase a new control plate online and will be waiting for it. As I do, I also decided to buy some banjo replacement buttons from StewMac - I read in another post that you can use these to mod Y tuners to make them look more "Hofner-y". So, since I am not in a hurry, I am going to try that first before modding the headstock for the larger Hipshots. I can always mod the headstock later if I want to, but after reading the replies I think I will try this first - it won't require any woodworking on my part. After having everything in hand, I am not sure the Hipshots will look right on the headstock anyway...I might change my mind there, but I'll try this first. If I change my mind, I wanted to thank everyone for the suggestions because I will return to this thread as a reference. Have a great week everyone!

 

[Dan_reeves]

Went with this, for the time being. The banjo buttons came from StewMac for $5 each, helps me sort of retain the beatle bass vibe and no need to drill. Just as a follow up. Thanks!

 

[Beej]

Cute! I like it

 

[Dan_reeves]

Cute! I like it

It was the path of least resistance

 

[Matt Liebenau]

Cool. I never would have guessed that banjo buttons would fit on those tuners.

 

[Dan_reeves]

Cool. I never would have guessed that banjo buttons would fit on those tuners.

I found it buried in another beatle bass thread on accident. It was from a while ago. Pure dumb luck on my part. But they work great. The banjo buttons are actually a really tight fit, but they went no problem.

 

[rudy4444]

I found it buried in another beatle bass thread on accident. It was from a while ago. Pure dumb luck on my part. But they work great. The banjo buttons are actually a really tight fit, but they went no problem.

If you want something a bit nicer in a button you can find many buttons to retrofit Gotoh banjo tuners at Bob Smakula's banjo-specific website. He has beautiful buttons in Amber, Tortoise, grained ivoroid, real ebony as well as black, cream, pearloid stock buttons, and also keystone buttons in various finishes.

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Keystone Gotoh replacements in amber:

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[Matt Liebenau]

If you want something a bit nicer in a button you can find many buttons to retrofit Gotoh banjo tuners at Bob Smakula's banjo-specific website. He has beautiful buttons in Amber, Tortoise, grained ivoroid, real ebony as well as black, cream, pearloid stock buttons, and also keystone buttons in various finishes.

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Keystone Gotoh replacements in amber:

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Purty!!!

 

[TrustRod]

I use a large round file larger than the diameter of the finished hole but instead of working it in and out of the hole I twist it back and forth when it is all the way in the hole. So I use it more like a reamer and the holes stay round.

 

[lokikallas]

I just used a reamer to do this. The ultralights were just a little bit bigger than my existing holes. I used the 5/8” reamer all the way through and they fit like a charm with no issues with chip out on the painted headstock.