Official Luthiers Forum!

I was re-reading the excellent series of articles on Charles Fox written by Mark French for American Lutherie (Nos. 139-144), and ran across this hint that can save a person some money on drill bushings for jigs, fixtures and templates. Charles apparently uses ball bearings instead of actual drill bushings.

I like using 1/8” index pins in my guitar building, but have often complained (to those who will listen) about how expensive drill bushings are. So, I thought I would order some ball bearings and see if they would be suitable.

Here is a typical drill bushing that I use (cost: in the $8 range), alone and with a 1/8” drill bit in it:




Here is one of the ball bearings I ordered (cost: in the $1 range), alone and with a 1/8” drill bit in it:




These look and feel as if they will work just fine, and they are waaaaay less expensive than actual drill bushings. Thanks to Charles Fox for this small hint, along with all the other great contributions he has made to this endeavor!

Excellent tip, thanks for bringing it to our attention.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

My pleasure. I will offer one potentially adverse observation: There is a little more play in the inner diameter of the ball bearings than in the drill bushings, and the drill bushings are taller, so they are more capable of keeping the bit going straight while you drill. So, if you use these to drill holes, and the holes need to be super duper precise, the drill bushings are probably a better idea. But if a little play is OK for the task in question, the ball bearings look like they will be just fine, and definitely a lot easier on the wallet. And for something like mating with an indexing pin (instead of drilling holes), maybe a little play is a good thing.

I make drill bushings out of hardwood on the drill press. I use them where I can’t fit the object to be drill into the drill press. When the fit gets sloppy, I drill another one.

Here's something I really like when I need a precision hole in something I can't bring to the drill press. It also has a V-groove machined into the bottom for cross drilling a rod or cylinder.

https://www.amazon.com/Big-Gator-Tools-STD1000DGNP-V-Drill/dp/B0061FY004/ref=sr_1_9?

Thanks for the tip on shorter links Dennis!

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Brian R, Wood Mechanic
N8ZED

Great idea!

Ball bearings are also useful for calibrating a CNC machine. Mill a plug that fits in the bearing hole, and a hole that the bearing fits into. If the plug is loose in the bearing but the bearing fits just right in the hole, you need more backlash compensation and smaller tool radius.

rbuddy: When copying ridiculously long links like that, you can generally delete everything after the question mark. It's just tracking info which tells amazon that you are the one who posted a link on this web site anytime one of us clicks it.

I have stacked bearings to make a taller drill bushing. Easy to tape a group together on their outer surface, make them as tall as you need and still be money ahead.

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jw ( o)===:::

Great tip, thanks!

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Measure Twice,

Karl Borum