Tuesday, July 28, 2009

How to upgrade guitar tuners

A very common guitar upgrade is to swap out crappy, cheapo, open-backed (or “stamped”) tuners and replace them with better, enclosed die-cast tuners. I’d like to show you how to do that, and point out a few potential dangers along the way. The example shown uses an acoustic guitar with 3-a-side tuners, but you could follow the same process for an electric, be it 3-a-side or 6-in-line.

Click on any of the images to see bigger versions.

Here’s the patient.

The guitar itself plays well and sounds pretty good, but the tuners have become almost impossible to turn, so it’s time for a change. Although these may look like enclosed tuners, they are simply open-backed tuners, with nothing more than a back cover, which doesn’t even stop dust from getting in.

Decent enclosed tuners can be had very cheap these days. This particular guitar didn’t really warrant Schaller or Grover tuners, but the replacement no-name tuners it is about to receive are a huge improvement over what was there before. I should mention here that if you have a very expensive or collectible guitar, you should probably try to replace your tuners with exact matches if at all possible.

First thing to do is remove the strings. After that, these tuners are removed very simply by unscrewing the little retaining screws, as shown here.

The bushings (also known as ferrules) also need to be removed from the front. The trick here is to stick something like a screwdriver into the hole and then gently roll it around so that the bushing slowly works its way out.

Time for a little cleaning.

Now we’re ready to start the work required for the upgrade.

Unfortunately, enclosed tuners generally require larger holes than open-backed ones. The holes on this guitar appear to be a little over 7mm, but as you can see below, the new tuners in this case will require a 10mm hole.

I got this handy hole-sizing gauge with my drill bit set.

As you can see below, it also measures the enclosed tuner at 10mm.

This is one of the two tools required for enlarging the holes. It’s called a reamer and it really is the perfect tool for enlarging already-existing holes.

I put the reamer through the same 10mm hole on the gauge and mark it with correction fluid. Alternatively, you could mark with a pen, or tape, or whatever you like.

We ream out the hole until the mark meets the wood, then stop. In fact, I would advise you to go just a little bit farther, but not much. The reasoning here is that if you make the opening of the holes a little bit bigger here, you are less likely to chip the finish during the filing process described later.

We do the same to all 6 holes, then repeat the process from the other side of the peg head.

We now have a situation where the opening of the holes on both sides of the peg head are 10mm, but since the reamer is tapered, the hole is not 10mm the whole way through, so we need to do a bit of filing to correct this. Although this photo shows the file being inserted from the back of the peg head, I advise you to insert it from the front. That way it is less likely you will chip any of the veneer off the front of the peg head. If anything chips off the back, it is a lot easier to hide it under the tuner, although in fact, chips from the back are less likely anyway.

Once all 6 holes have been filed, and you have checked them all to make sure the tuners fit, it’s time to screw the tuners into place. Line up something straight, like a ruler, against three of the tuners and make a mark in the holes for the retaining screws. Then do the same for the other 3 tuners.

You could use a drill to make pilot holes for the retaining screws, but I prefer one of these. It’s much easier to control and less likely to accidentally go right through the peg head (and believe me, you really don’t want to do that). It’s called a pin vice (or vise, depending on where you come from).

Whichever method you use, remember that these are just pilot holes, so should be thinner than the screws themselves. Don’t be tempted to just screw in the screws without the pilot holes. There’s a very slim chance you’ll split some wood, but there’s a very BIG chance some of the screws will actually snap on the way in. Last thing to remember is that you should mark the drill bit beforehand so that you know when it has gone deep enough for the screws, but not so deep that it goes right through the peg head.

I recommend that you screw in the retaining screws, but not too tight, then screw on the bushings from the front of the peg head, using a socket (in my case, 10mm). Finally, tighten up the retaining screws. You may even want to use your ruler again while you’re doing this.

Anyway, here’s the finished result (the new tuners got switched from gold ones to silver ones at the last minute, before you ask). As you can see, the back isn’t pretty, but it’s functional, which is all that was required in this case. A set of machine heads with offset retaining screw holes would’ve hidden the footprint of the previous tuners a bit better, so that’s something you may want to keep in mind if appearances matter to you.


daniel said...

Awesome! It took me like a week to get all the correct terms and tools which after a series of google searches, led me to this blog. Thank you very much on this informative post, I now have the confidence to do this myself and not pay someone to do this seemingly simple (on paper) task.

Let's hope I don't fail horribly on this project and catch my guitar on fire somehow. lol

Richard Holland CFRE said...

Great info on a very helpful blog! I am looking for tuners / machine heads with a diameter of 10mm on the shaft/roller, for a bass guitar, and that's actually how I stumbled into here. Do you have any suggestions where I can these, preferably in the UK? Thanks in advance. Rick

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