Official Luthiers Forum!

Say you've got a neck that is already drilled but a body that is not, what do you do?? Thanks!

With the bounty of cheap imported components these days, I've been contacted by more people trying to put guitars together and need help. I don't mind doing it, I just like to be really clear of what I'm getting into.

Pat

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Pat

Start measuring...

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Peter Havriluk

I think the simplest solution is to cut a block the size of the mortise and install (using a drill press) drill bushings in the block. Clamp the block in the mortise and drill the holes with a powered hand drill. Once the holes are there, use a reverse counterbore bit (a spot facer) in the hand drill to create a pocket around each bolt head.

Acoustics or electrics?

Yeah, but that just does not seem very accurate.

Pat

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Pat

If it uses end grain inserts -- then I would make a bolt with a pointed end - then position my neck and mark the holes - then drill.

Along the same lines as Simon mentioned:

https://www.youtube.com/watch?v=8WxF6zDjvpk

One word - dowel centers. Actually that's two words

https://www.rockler.com/dowel-centers

If your problem is what I think it is, these are great. My daughter and I positioned the necks on 9 StewMac ukulele's in about 30 minutes for a uke building class she was giving

Ed

If you're asking about acoustic guitars, dowel centers are the ticket for marking where to drill the head block.

If you're asking about something like a pre-drilled Strat neck to go on a body that doesn't have the holes drilled in the neck pocket, I've read of people using nails of the appropriate size inserted into the screw holes in the neck to serve as dowel centers to mark where to drill the body.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I'm going to assume partscasters. We use inexpensive SAE and metric transfer punches for this an any other job that requires matching a pre-bored mounting hole with another component.

Good quality transfer punches are a pleasure to use, but these will get the job done, and what we have out for use by students and for most bench work:

https://www.mscdirect.com/product/details/04293171

https://www.mscdirect.com/product/details/00422527

Here is a low-cost Harbor Freight set:

https://www.harborfreight.com/28-piece- ... -3577.html


Individual punches can be purchased on Ebay or through most machine supply shops such as MSC Direct.

For acoustics, such as where we are performing a neckectomy and conversion to a bolt-on neck (e.g., those epoxy-glued Yamahas from the mid-1970'd onward), it is easier to create the holes in the neck block using s shop-made alignment jig, counter-bore with a reverse spot-facer or 5/16" drill rod-piloted Fuller four-flute counter-bore with stop collar, then transfer using a punch to the end of the neck. Where there is no access, dowel centers work pretty well for the job as already mentioned.

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For the times they are a changin'

- Bob Dylan

Why not?

Assuming first this is an acoustic guitar then I would imagine the fret board is glued on the neck too? Measure from the fretboard to the center of the holes. Then mount a flat piece of wood on the guitar top so that it over hangs the head block. You can just hold it there really. That acts as your fretbaord. Do the same measurements and it will be accurate enough. Of course everything needs to be in a straight line for this to work.

I used to do what Simon had mentioned, though I just used a drill bit to make the mark, and also in reverse so that I would predrill the head block but mark the neck holes, but found it more accurate to just go right ahead and measure it. For this operation it's nice to have drill bits that are slightly bigger then your bolts so that you can fudge it a bit as needed.

And as was mentioned a reverse bit of some kind will make nice mounting holes on the inside of the guitar. I use this technique when resetting necks with the 'sawed off' method bolt on conversion. You can take a spade bit and ground in a blade on the reverse side and it works like a charm.

Yep, dowel centers and transfer punches will cover most scenarios. A set of transfer punches is one of the better investments in lutherie.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

If it's an acoustic guitar with bolt holes already in the neck, dowel centers make measurements unnecessary. Put the dowel centers in the holes, put the neck in place on the body, and either press on the heel or give it a light rap with a rubber mallet. The exact locations to drill are marked on the head block. Fast and precise. I drill the holes in the head block free hand with a brad point bit. The diameter of the holes is a bit larger than the diameter of the bolts so the holes don't have to be 100% dead on straight. The drilled hole are the same diameter as the spot facer shaft though.

If it's an electric, Pat asked about the situation where the neck is already drilled, but the body is not. If he's asking about a Fender-type bolt-on neck, transfer punches wouldn't be useful, although they certainly would be useful in the reverse instance of the body having been pre-drilled, but not the neck.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Don't do it, parts guitars are a long walk on a short pier.

Otherwise what Woodie said.

PS: We don't work on parts guitars unless it's been a successful (subjective I know...) playable guitar and we can evaluate it with strings on before deciding if we want to get any one us.

Thanks guys! However, yes I was referring to a partscaster. And it is the neck that is already drilled, so the only thing mentioned so far that sounds like it could work would be nails. I guess if they were cut to the right length so only the tip was sticking out it could work, but that does not seem incredibly accurate either.

I guess you could do the holes just slightly oversized to account for any indiscrepancies, but I wouldn't feel all that comfortable because it seems like you want that type of neck super rock solid.

I get your drift Hesh, and have not accepted this job yet. I had another guy basically bring over a whole bag of parts! I told him to leave it and I would look at it and come up with an estimate. Have not looked at it yet...... In hindsight, I probably should have charged a half-hour just for the estimate.
Pat

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Pat

Pat - If you go ahead with the project, there are several approaches to the problem given in these two discussions:

https://www.tdpri.com/threads/how-to-drill-neck-holes-in-a-body-to-fit-a-pre-existing-neck.322928/
https://www.jemsite.com/forums/f21/what-best-way-drill-neck-holes-new-body-18213.html

Some sound better than others.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

The most efficient way is to plug the holes in the neck and start fresh.

Just remember - you will forever be the "Father" of these guitars with all that entails.

Bing bang boom, that's what I would do too.

One more thought.

Since most "casters" have a plate for the where the neck screws meet the body, weaken some double stick tape (fingerprints) and position the plate on the neck. Stronger double stick tape in the pocket. Align the neck and press into place. Remove the neck leaving the plate in place. If it aligns well with the body drill the holes. If not, plug and start fresh.

Steve

Another vote for dowel centers and transfer punches.

And for drilling the tenon of an acoustic guitar neck, I use one of these self-centering doweling jigs. I'll mark the location of the hole; position the jig; snug it up to the point that it stays put but lets me slide it with minimal effort; and check with a flashlight to make sure the jig is positioned correctly. As long as my mark is on center, I'll snug the jig fully and drill.