headless bridge design for machine shop?

[Guitrying]

I'm interested in an option briefly mentioned in an old thread here, post by DandHCustoms,

 although he no longer appears to be active here so I'm assuming that his promised design will never be forthcoming. Does anyone else have such a design, and if so, how easy would it be for a non-engineer to tweak?

I ask because I want to make a headless guitar, but I'm classically trained fingerstyle player, don't use a pick even on my electrics, and therefore want an extra-wide neck. I'll be buying a Warmoth neck for the project, either 1 3/4" or their superwide (for electrics) 1 7/8", but currently my only options for headless hardware at these neck widths are individually placed single nuts and saddle-tuners from ABM, Mera, or Technology4Musicians but I'm just a neophyte builder and individually placing both the single nut for each string and each individual saddle is way more than I want to bite off at this stage. Unfortunately neither Hipshot nor Jcustom offer nuts that will accomodate 1 3/4", let alone 1 7/8".

So I was beginning to think I was hosed--then ran across the above comment on this forum. That kind of thing could well be the answer to my problems. So, question #1: does anyone else have such a design?

But there's a wrinkle. even if DandHcustoms popped back up with his bridge design, it likely wouldn't support the neck width I need. (The entire reason for this project is to get that extra-wide string spacing, at least extra-wide to most of you, so that's non-negotiable.) So, question #2: if such a design exists, how easy would it be to tweak it to my idiosyncratic needs?

[curtisa]

How about buying the individual headless tuners and attaching them to a fabricated baseplate with the required string spacing? The only part that would then require any real degree of precision would be drilling the mounting holes at the required positions on the plate.

[Guitrying]

Intriguing. OK, for the moment setting aside the technical issues of how to do that, there's a possible bridge solution. But the same problem is still there for the nut. Would it be possible to just attach the single nuts (e.g. https://abm-guitarpartsshop.com/ABM-GUITAR-PARTS/Headless-Systems/Guitar/Headpieces/ABM-7010b-Black::436.html) to a similar plate up at the head?

[curtisa]

That's pretty much exactly what I do with mine. Admittedly this is done on CNC, but it doesn't have to be that fancy:

A fabricated mounting plate to fit six tuners (or nuts) would be a trivial thing for a capable machinist to whip up, provided you gave them a decent drawing of what you wanted. It's the sort of thing they might do for a six pack of beer in their lunch break if you ask nicely. Certainly a lot less work and money than fabricating up six custom-made tuners specifically for your build.

If you have access to an OK-ish drill press there are ways of making repeatable, equally-spaced holes in straight lines that don't require a lot of high precision operations.

[Guitrying]

Nice-looking head on that axe! I do have access to a drill press (a relative's entire well-equipped shop). But as I said above, I'm a neophyte at this--I've done a bit of woodworking in the past, but that's it. Where can I find out more about "ways of making repeatable, equally-spaced holes in straight lines" on the drill press? Can you point me to a good youtube video or an informative site? I'm assuming that you use the special metal-cutting bits and then manually tap the screw holes shown in your photos. I don't need you to point to info on tapping the threads, that's no problem, but the initial creation of the nut remains outside my wheelhouse at the moment.

I'm also assuming that all the same procedures would hold for the bridge. If not, I'd much appreciate the correction. And thanks a ton for responding so far.

[Bizman62]

1 hour ago, Guitrying said:

Where can I find out more about "ways of making repeatable, equally-spaced holes in straight lines" on the drill press? Can you point me to a good youtube video or an informative site?

How about this:

 

[curtisa]

Kinda. The temporary fence at the back of the table is correct, as it allows the workpiece to slide left-right to prevent any error in the forwards/backwards placement of the holes. But the extra jig with the locating pin she uses potentially re-introduces those placement errors, as there's nothing stopping the jig rotating round the axis of the index pin (at 11:14 for example you can see the second-from-the-right hole is closer to the fence than the other five). Better results would have been attained if the jig with the pin was wide enough such that it too could also be pressed up against the fence at the same time as the workpiece, so that it couldn't be accidentally swivelled around when positioning each hole.

The other alternative is to use the long fence at the back of the table as before, but construct a stop off to one side that the workpiece gets butted up against to prevent it shifting from side to side (similar to those adjustable end stops you find on chop saws). If you can make this side stop adjustable in some way that you can incrementally shorten it in discrete steps you should be able to achieve equally spaced holes without the aid of measuring/marking anything except for the first hole you want to drill. The only trick is finding something that has the same thickness as the string spacing you want to achieve as you add or remove components of this side stop (maybe six Lego blocks, or six holes in a Meccano girder, or six offcuts of some metal bar stacked side-on-side?). Something like this:

 

6 hours ago, Guitrying said:

I'm assuming that you use the special metal-cutting bits and then manually tap the screw holes shown in your photos

Yes, although you don't have to tap the holes if you don't want. You could just as easily drill the holes in the baseplate all the way through, use longer bolts with nuts on the underside to secure each nut/bridge and route out some clearance in the timber underneath the baseplate to allow the nuts/bolt ends to fit in to. The only drawback then is you have to design your baseplate to be intsallable with all six nuts/saddles already in place. The nut plate in my photos, for example would need to have wider sides to allow me to install some mounting screws to attach it to the headstock.

[Bizman62]

Thanks @curtisa, I had that nagging feeling in the back of my head already when I first watched that video a couple of years ago but I couldn't figure out what the issue was or how to do it better.

Your video reminds me of something Neil Paskin may hove done. It wasn't too hard to find an example:

 

[Guitrying]

Thanks a ton, folks. Really appreciate it. I'll chew on these vids and maybe make some initial experiments in wood before trying metal for real. But also, how do you make the initial plates? Find some flat piece of metal and then hacksaw it, then grind the edges to the right size? Or can you get right-sized plates from somewhere?

[curtisa]

Use whatever is most convenient to you (hardware store, scrap metal yard etc), although starting oversize and cutting it down to shape after the holes are drilled will probably make life easier. If one edge is straight from the factory to begin with (say the long edge of an aluminium bar) you'll get a head start on the accuracy of the hole placement using the fence on the drill press.

 

[Guitrying]

Thanks for the tip on starting bigger. I wouldn't have thought of that. And trying to use a straightedge on the metal too. Good stuff.