radiusing guitar neck.

[jim mills]

I was asked by a local luthier if I could help him radius some guitar fingerboards on my shaper. The task would involve building a jig to hold the fretboard blanks vertically, then using my shaper and a knife ground to a 12" radius, shape the boards. Seems simple enough, but what say you? Thanks!

[Mike Sherman]

Depends on the size of the blanks he is supplying and if they are pre-slotted. The only way I'd radius FB's on a shaper is with a vacuume fixture.

[Kevin L. Waldron]

Don't re-invent the wheel..... This is discussed in Ukulele Underground...

supplier = http://sje-tools.com/collections/router-bits

Blessings,

Kevin

[jim mills]

Ok, so now he tells me the fingerboards will already be attached to the neck so the truss rod can be preloaded.

[Kevin L. Waldron]

Your choices are now more limited......

CNC or buy / make something similar to this piece of equipment or muscle and a sanding block.

http://grizzly14-px.rtrk.ca/products...ent-Only/G0577

Blessings,

Kevin

[John Coloccia]

Personally, Jim, I can think of a lot of reasons to simply not get involved with this project.

[Larry Fox]

Personally, Jim, I can think of a lot of reasons to simply not get involved with this project.

This! I would run, not walk in the other direction from this one.

[jim mills]

While I will say that that Grizzly contraption looks typical of something they would sell, I dont see the problem with attempting this. No liability on my part, and the knives wont cost me anything. I've come up with a jig design that incorporates a dovetail in it to match the dovetail cut in the guitar neck. Blocking and clamps hold the headstock end. The jig bolts to the sliding table on the shaper, and the cut will be extremely light. My concern is tearout or chipping at the fret slot, but I could fill those with some temporary filler strips. Seems potentially acurate with good setup.

[Julie Moriarty]

I've seen a lot of jigs designed to radius a fretboard, but none yet that uses a shaper. I've seen some complex jigs that use a pin router and some simpler that use a hand-held router. I took one of the latter designs and made this:

Something like this could be modified to take a full neck. You'd just have to make sure the neck is perfectly straight and level in relation to the router bit. Of course, each different size radius requires a new router base, or a router base with interchangeable sides. Of course, it can't do conical radius fretboards.

When you do a Google search, it's amazing to find how many ideas are floating in the collective minds of guitar builders.

[Dennis Peacock]

This is what the guy needs for doing the radius on the FB's.....

http://www.grizzly.com/products/Guit...g-Sander/G0574

[Greg Savage]

personally, jim, i can think of a lot of reasons to simply not get involved with this project.

bingo!!!!!!!!

[Steve J Evans]

Run away! Particularly when the Builder is wanting to build and preload the truss rod before radiusing! Why would he want to do that?

If you use my router bits - it totally feasible to make a jig to hold the neck level to the bit, sure there is more work involved but it's possible. Just as it is for preshaped fretboards that can be held level on a square block. I have already tested my bits at 10k rpm for use in a shaper (they work fine)


Cheers
Steve (sje)

[John Coloccia]

Run away! Particularly when the Builder is wanting to build and preload the truss rod before radiusing! Why would he want to do that?

It's not too unusual. He likely has a single action rod, and we wants to load the neck into a bit of back bow before flattening. This will ensure that the rod always has tension on it (a good thing, or it will rattle), and it also gives you a little insurance against a back bowed neck you can't fix. He's turning it into something of a double action rod. There's also some thought that having some stress on the neck makes for a more stable neck, though I can't say if that's true or not.

I can't speak for every builder here, but I'd bet dollars to donuts if you asked 10 builders what they think of farming this out to a guy with a shaper, 9 of them will immediately say, "Why doesn't he just radius the necks himself?"...because it's such a simple and straightforward task that the idea of going through the trouble and expense of getting someone else to do it is a little crazy. The 10th guy will say, "I tried that once...." For that reason alone, I'd stay away from this project because my gut tells me this will be a problem customer. I can think of other reasons having more to do with the logistics of properly aligning and clamping the neck in a way that will achieve the correct results. It won't be trivial...there are no square edges, only tapered edges, and because of the backbow there will not even be a flat plane anywhere...and the neck is very flexible, so you can't just mash it down. But the first reason that came to mind is it doesn't make sense that a guitar builder would farm this out...red flag.

[Julie Moriarty]

For that reason alone, I'd stay away from this project because my gut tells me this will be a problem customer.

I hadn't even thought of that, John. It makes a lot of sense. When you mentioned the simplicity of creating a radius on the fretboard, my mind went to the "easy buck" angle, IF you weren't hell bent on using a shaper and you came up with a decent jig. The customer asking for the work to be done with the shaper was the part of this scenario I didn't get. Why would he care what tool you used, as long as the results were satisfactory?

[Matt Lau]

What John said +++++++10.

I hope the guy is paying you a ridiculous amount of money for this.
Buy preradiused pre slotted boards for the eventuality what thing blowout and chip.

I'd recommend huge belt sander or just using a sanding block.
The chipping would be terrible.