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Help drilling holes for tuning machine bushings
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Author:  Corky Long [ Sun Sep 05, 2010 4:36 pm ]
Post subject:  Help drilling holes for tuning machine bushings
There's gotta be a better way.....
I've got Gotoh tuning machines with a .250" shaft - not problem drilling those holes in my headstock with the jig that I have. These tuning machines come with a bushing that is .350" in diameter. I have a mental picture of a drill bit that has a pilot shaft of .250" and cuts a shallow .350" hole (or .348" for a snug fit) for the bushing. Does anyone use something like this? How do you cut the hole for the bushing?? (Previuosly I've used a risky and subious process of using a drill bit without pilot shank and drilled it out by feel - not interested in repeating this process. Thanks.
Author:  meddlingfool [ Sun Sep 05, 2010 4:37 pm ]
Post subject:  Re: Help drilling holes for tuning machine bushings
I think Stew-Mac sells them.
Author:  unkabob [ Sun Sep 05, 2010 4:47 pm ]
Post subject:  Re: Help drilling holes for tuning machine bushings
Could you take a bit for 0.035" dia. and have a local machine shop (or friend) grind the first half inch to 0.25" dia. ?

I would suspect that you would grind it in a lathe but if cheap matters, you might do it in a drill press with an angle grinder.

Be careful if you try it yourself.

Bob :ugeek:
Author:  Kent Chasson [ Sun Sep 05, 2010 6:01 pm ]
Post subject:  Re: Help drilling holes for tuning machine bushings
The stew-mac bits are worth it if you plan to do more than one. Another option is to drill your 1/4" holes in the headstock, clamp a board to the drill press table, drill a 1/4" hole it it, super glue in a short 1/4" dowel, chuck the correct sized bit in to the drill press, position the peghead so the dowel goes into the tuner hole and your larger bit will now be centered over the hole and stay there.

You may need to put the drill press table off center and locate the dowel fairly close to the edge of your board in order to be able to keep the peghead flat on the table as you drill the holes closest to the neck shaft.

Also, I've gone to drilling oversized holes for the bushings and gluing them in with CA. Wedging bushings in seems like a great way to split a peghead veneer.
Author:  Fred Tellier [ Sun Sep 05, 2010 6:14 pm ]
Post subject:  Re: Help drilling holes for tuning machine bushings
Drill the bushing hole 1st with the .350 to needed depth, then drill the .250 from the bottom of the bushing hole. This advise was posted in the past by Mario if I remember correctly.

Fred
Author:  Corky Long [ Sun Sep 05, 2010 9:04 pm ]
Post subject:  Re: Help drilling holes for tuning machine bushings
Thanks, all!

Fred Tellier wrote:
Drill the bushing hole 1st with the .350 to needed depth, then drill the .250 from the bottom of the bushing hole. This advise was posted in the past by Mario if I remember correctly.

Fred


Aaah. That makes sense. If only I hadn't already drilled the .25" holes.... [headinwall] Next time.

The Stewmac bits ..... yep..... I guess if I'd gone to the trouble to describe them that specifically, I could have checked Stewmac and LMI. Doh! duh I think I'll probably get that set.


Live and learn... On the bright side, this guitar's almost finished.. :)
Author:  Howard Klepper [ Mon Sep 06, 2010 1:22 pm ]
Post subject:  Re: Help drilling holes for tuning machine bushings
Lots of ways to do this. Besides letting the bottom of your larger hole center the bit for the smaller hole, you can through-drill the .25" and then set a 1/4" dowel as a pin under your bit to align the holes for the larger bit.

With brad point bits, you can drill the small hole with a stop set so just the brad point goes through, and then use that hole to center the brad point on the larger bit freehand.
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