Tuner hole drill bit

[Warren May]

What is the best drill bit for drilling tuner holes (10 mm) for Schallers, etc, in paddle type headstocks? I've bought Dewalt and Hitachi twist drills from the big box stores but they don't drill a nice clean hole for me. Sizes are limited. Also, they tend to grab and chip wood. I bought the tuner alignment jig from StewMac but it uses a 1/4" bit and, so, the tuner holes have to be enlarged.

Seems like a similar jig with different size bushings and bits would be good to have. You could position it and clamp it in place but use different sized drill bits with stops and bushings to get the properly aligned tuner holes.

[Bob Gramann]

I use a small bit as a pilot to drill all the way through (and mark the hole on each surface). Then I drill half way through from each side with a Forstner bit. No breakthrough--a clean hole every time. I've also used a 10 mm brad point bit but I went to the Forstner when the brad point bit got enough wear on it that I didn't like its cut.

[Chuck Tweedy]

Warren, the best drill bits to use for cutting wood cleanly are "brad point bits" that have a guiding point, and cut first on the outer edge of the cutting face. Also, you must back the work with solid wood and drill into the backing - drilling into open space will always lead to bad chip-out.

That being said, if the cut is made in a well controlled way - like say on a CNC mill - then even a standard tip twist drill can cut a perfectly clean hole in wood. The issue is how well the work is constrained, and how controlled is the feed-rate. On a good mill, the tool can not "self-feed" at all, and therefore, the chip thickness is totally uniform. If you are using a hand-drill or even a reasonably good quality drill press, the tool can (will!) self-feed too aggressively into the wood and tear-out giant chips.
Also, if the workpiece needs to be held solidly in a vise so it can not move either side-to-side or up-and-down.

The brad-point bit does these things for you - it self centers the work so it can not move side-to-side.
It will still self feed, but that is usually after it has cut a clean entry hole - so at least it looks good on the outside.

[Steve Senseney]

Another "method"--cut undersized holes, and gradually enlarge with a tapered reamer. You won't have very much tearout, and you will be able to get the amount of oversized hole you want.

[Dave Stewart]

By far the best bit IMO is the 10mm "lipped" brad point bit, avail at Lee Valley. Very clean hole & sharp as a razor!

[Warren May]

Thanks for the suggestions. I've used brad point bits and my drill press for the tuner holes in the past but I bought the StewMac tuner hole jig to make things a little more accurate. I often have trouble getting the holes to line up perfectly and thought the jig would help in that regard. If I can't figure out how to make the predrilled 1/4" holes work, I think I'll abandon and buy a new bit from Lee Valley to try it out. Since the jig already forces you to drill the 1/4" hole, there isn't anything for the brad point to bite into.

Based on the reamer idea, I'll try out on scrap by drilling successively bigger holes. Maybe part of the problem was drilling the 1/4" pilot hole and jumping straight to the 10 mm bit.

[Darrel Friesen]

By far the best bit IMO is the 10mm "lipped" brad point bit, avail at Lee Valley. Very clean hole & sharp as a razor!

I agree with Dave. I clamp the headstock to a backer and use the drillpress. Clean and no tearout.

[Nick Middleton]

Since you're installing schaller's and you're using StewMac stuff I recommend this too:

http://www.stewmac.com/shop/Tools/Reame ... eamer.html

This will make the tuners on the back side of the peghead fit without the top being over-drilled.

[Ron Belanger]

+1 Nick

[Warren May]

Thanks, Nick. I ordered the reamer from StewMac and will try it out on the next build. It wasn't much more expensive than a good 10 mm bit and the stepped approach looks like a good idea. I've been drilling a 13/32 hole all the way through but the stepped reamer might be good. Do you have any issues with clearance for the male part of the tuner using the suggested 5/16" starter hole?

[Nick Middleton]

No I haven't had any problems with it. StewMac used to only sell a step-bit that could drill the hole and the counterbore in 1-shot, but it's like $70-80! When this counterbore had come along I ordered it immediately!

[Warren May]

I got the order in from StewMac for the reamer they offer. It's a really great tool for this and works perfectly. Thanks so much, Nick, for the pointer. I agree with you about the price. It's definitely worth checking out. It also looks like it might be easy enough to touch up with a stone when it gets dull.

[Nick Middleton]

Your're welcome. I haven't drilled enough holes to need to sharpen mine, but looks no more difficult than touching up a straight router-bit. It should last a good while.

[Randy Cordle]

I've drilled literally hundreds of tuner holes using a simple hardwood guide block in conjunction with a scrap of backing board with the head stock clamped in between. Here's a quick picture showing a banjo peg head, but I use the same process for larger diameter machine holes.

[Mark Swanson]

That's a good idea. And for three in a line tuners, or for four in a line mandolin tuners, you can make your guide block with the proper spacing and place it in the correct location on the peghead, in line where you want the tuners. Then it'll guide your drill bit and correctly locate the tuner spacing too.

[Paul E Buerk]

To keep things lined up, I just use a fence on the drill press table with a backing board underneath. Seems to work just fine with a standard twist bit, but I'd agree that a brad point would be better.

[Gordon Bellerose]

I went ahead and splurged on the tuner bit sold by stewmac. It is a single bit that drills a 2 stage hole. The 10 mm hole for the tuner body, and a smaller hole for the top of the tuner. Once you get the depth set, it is a really easy tool to use.

[Warren May]

I agree Gordon. When you mention setting the depth stop, not sure I understood based on the design since the reamer and pilot portions are preset? It easily solved the problem of using a twist bit for me since it is a reamer that doesn't catch the work like the drill bit does. I've now drilled/reamed 4 headstocks with it without a hitch. I need to add a 5/16" forstner bit if I can find one to make a safer system. Well worth the money.

[Gordon Bellerose]

Actually I am using a 2 stage drill bit. Here's a link to it at stewmac. As I am using Gotoh tuners, so it works well for me.

http://www.stewmac.com/shop/Tools/Drill ... l_Bit.html

[Warren May]

My apologies for not reading more carefully.