Official Luthiers Forum!

What is the best type of drill bit (brad point?) for enlarging the end pin hole for after market pickup installation?

How many stages do you use in drilling to reduce risk if tear out? (pilot hole + what sizes?)

Do you use blue painters tape over the existing hole or is there a better tape to reduce risk of tear out?

Thanks in advance for your help and expertise!
Ed

I like to use a two flute step up bit, though it can leave a bit if tearing on the inside.

http://www.stewmac.com/shop/Tools/Speci ... 3&xsr=5110

I start with a .250 brad point bit, then follow up with this for the endpin jack as needed.

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John Mayes
http://www.mayesluthier.com

Thanks, John. I had forgotten about that StewMc reamer. Looks like a great low-risk method.

1/2" step bit.

http://www.amazon.com/Irwin-UniBit-16-I ... B00004THYY

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Thanks much for the link, Howard. This bit is MUCH cheaper than the StewMc reamer. Roughly what speed do you use? Ever have any tear out problems with it?

Double post.

Ed,

I just used the bit Howard mentioned. I don't know what rpm my drill runs at, but it's a Dewalt 18v three speed. I had it in second gear and at about 3/4's throttle. It left a nice clean hole with no tearout inside or out.

Steve

For a new hole, I find these lipped brad points from LV hard to beat. Zero tearout.
http://www.leevalley.com/en/wood/page.a ... 2240,42247

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Dave
Milton, ON

Indeed, those Lee Valley bits are stellar for all kinds of drilling, and are well worth the cost. W.L. Fuller in the U.S. also makes excellent brad point bits. In fact, they used to supply Lee Valley. I find both companies equal, but Fuller makes custom bits to spec. One thing those brad point bits do not work on is endgrain. They tend to just smoke up, especially in hard exotics. They are strictly for face or edge grain.

One other thing about the Brad point bits is that they do not exit as cleanly as they enter. Ideally, some scrap material should be pressed up against the exit location, to provide edge support, for the cleanest possible exit hole.

I use a step drill.

About the Lee Valley bits, they are nice and cut clean but the tips are fragile and they have a tendency to keep a thin plug of wood in the bit after exiting the hole. This makes it problematic to drill successive holes without stopping the drill after each one to clean out the plug. Major pain.

Where they excel is for precision location of holes for jigs and such. The fine point and accurate milling pay off there.

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http://www.chassonguitars.com