This is How to Make an Acoustic Guitar – Part Thirty One – Tuning Machine Drilling. In this part of the series, I’ll show you how to drill the holes in the head stock for the tuning machines, and give you some helpful tips for the process. Enjoy.
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Drilling the Tuning Machines
Drilling the tuning machines is a fairly straightforward process, and on the surface it seems like six little old holes that can’t really cause much of a problem. That’s where the problem actually shows up, because these six little holes are pretty darn important.
Though it’s not super difficult to get this part of the process right, it’s something that you do need to pay a little extra attention to for a couple reasons. First, the headstock is a very visible part of the guitar, so it needs to look good.
Second, it’s easy to tear out a little wood as the drill enters the headstock, which can make it look ugly. Finally, you can blow out the back side just as easily, but there’s a solution for all of that, and I’ll show you what you need to know.
If you missed last week, you can see How to Make an Acoustic Guitar Part Thirty right here.
Alignment and Marking
First of all, don’t even think about making any drill holes until you have the tuning machines that you’re going to use on the guitar in your possession. Unless you know the size, and you’ve used them before, and you’re buying the same thing, don’t risk it.
Even if you know the measurements, it’s just better to have them with you. This way, you can use the actual tuning machines themselves as an alignment guide, and you’ll actually be able to see what the heads look like, and where the posts will reside.
Once you have them with you, use them as a guide to help with placement. Measure and mark the locations for the drill holes, and if they are equal distances away from each other, or symmetrical for the left and right sides, you should make a jig.
Making a Drilling Jig
I recommend making a jig anytime you have to drill holes in a spot it’s going to be super visible. Especially if they need to be equal distances away from each other, or they need to look the same from left to right.
This may sound silly as you’re reading it, but go out into your shop and try to drill six holes that are all the same distance away from each other on the first try. It’s not quite as easy as it sounds, and if you mess up, it’s a lot of work to get you back to zero.
Instead of making this mistake, make a small guide from a piece of wood that has all three holes in exactly the right places. If your tuners have ferrules with them, you’ll only need one guide that is the size of the larger bit for those ferrules.
You can make a guide out of any nice piece of hardwood that is about a quarter inch thick. The guide is really more for placement than anything, so it just needs to be thick enough to capture the drill bit before it enters the headstock.
See Also: My Guitar Fretboard Slotting Jig
Watch the Headstock Angle
Something to be careful of when you are drilling your head stack, and a more frequent mistake than you might think is drilling your tuning post holes on an angle. After all, the headstock is also on an angle, so it can be easy to make a mistake.
Most drill press tables slide around, but most people also keep them centered. On the average drill press, you won’t be able to lay the headstock flat on the table and drill holes. There will always be at least a little bit of angle.
Before drilling, build up the table by laying a few pieces of wood under the headstock. This will raise that portion of the neck up words, and allow you to position it in a way that is flat. Doing so will mean holes that are perpendicular to the headstock instead of angled.
Drill the Big Hole First
This part of the process is only if your tuning machines have ferrules. These are those tiny little decorative pieces that trim out the hole, and your tuning post goes through the middle. They are common on guitar tuning machines.
Since you’re going to need to drill two different size holes, it’s important to note that it’s easiest to drill the larger hole first, and then the smaller one. Especially if you are using Forstner bits to drill, you need to have some meat in the center for them to grab.
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When you drill your larger hole first, it will create a low point in the very center, and that will aid in the tracking of your next bit. You won’t have to worry as much about the bit going through properly, because it will naturally work its way to the bottom.
A drill is a very lazy tool. It takes the path of least resistance every single time, which is why drilling holes is actually one of the more difficult woodworking operations. In this case though, the easy path is the right path, so you don’t have to worry.
Use a Backer Board Under the Headstock
Depending on your drill press, you may have already accidentally created a drilling backer just to get the headstock angle perpendicular to the drill bit itself. However, if you didn’t, this is an important part of the step.
As the drill bit exits the headstock, it will have a tendency to rip off and push out wood fibers as it breaks through. This can throw chunks of wood off the back of your head stack that may not be covered by the tuning machines on the rear side.
To prevent this, all you have to do is use a sacrificial piece of wood underneath the headstock when you drill, and make sure to drill all the way through. This will hold the fibers in place, and you’ll have a lot less blowout.
See Also: 25 Best Guitar Making Tips For Beginners
Test Fit the Tuning Machines
After you drill your holes, test fit your tuning machines, but don’t actually screw them down. Press fit the ferrules, and then slide the tuning machine itself in from the back side. If your design is different, follow the directions.
I recommend that you put all six tuners in place, and take a really good look at what they look like. At this point, if you need to make any changes, you can cut small dowels that fill the six openings and start again.
It’s going to be a heck of a lot longer process than that paragraph you just read, but it is something that you can do if you really messed up. The other thing you can do is just drill out the holes to a larger size, and plug with the same species of dowel as your neck.
You can also sand off the headstock veneer, and apply another one, and that will disguise your mistake and give you another chance. Hopefully you got it right on the first round, but there is an escape route if you need it.
See Also: Free Fret Bending Jig Plans
Coming Up Next Week
Next week the how to make a guitar series goes back to the body, and I’ll show you how to put an end graft on the acoustic guitar. This is a little piece of wood that trims out the lower side near the end pin.
Since the two pieces of side material meet right here, the joint between them needs to be trimmed in order to look nice. It also helps cover at the end grain of the sides, and prevents them from taking on or letting go of moisture too quickly.
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