Official Luthiers Forum!

Hand plane is good enough for me.

_________________
member of the guild of professional dilettantes

Is that really the ultimate goal? Are we aiming for and exact radius of a perfect circle. I agree with Jim in that this method creates a really nice fair curve, which IMO is the ultimate goal. I'm personally not aiming to hit an exact arc of a circle and would rather have something a little more fair than perfectly round. Just think this is a nicer feel and a bit more organic than perfect circles. But this has a lot to do with people's method of building as well. And I'm not sure one way is better than the other, just a personal opinion.

Does anyone believe it needs to be a circular arc?

James

I just use a block plane and plane to a pencil line. It's not complicated. There is no best way really but I think the OP might be asking about another problem here. The radius sanding dish should work just fine. If I understand the OP he is saying that he sands out the radius and then has a left or right tilt on the mating surface so that if the brace is glued it will not be at a right angle to the soundboard or back. The best thing to do when sanding anything on a sanding board is to take a few strokes then flip the work piece around and sand a few more and repeat. This eliminates any systematic error when sanding in one direction over time.

Yeah, there's probably someone who believes it. There's lots of people who believe things that aren't true.

_________________
A man hears what he wants to hear, and disreguards the rest. Paul Simon

+1

Dave F.

_________________
Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

It seems to me that braces cut to a radius as demonstrated aboce will not fit exactly a radius board if one is used for glue up. The only way to get a brace to fit a radius board is to sand the brace on the board.
Also it seems to me that wherever a brace is sanded it will be the same. It doesnt need to be sanded in position.
Please correct me if I am wrong.

What you need is a brace that fits the panel with no gaps and gives you your design curvature. One of the main reasons that circles/spheres are used is that any brace will fit perfectly on any panel of that curvature in any position/angle, without having to apply a heap of force. That is not true of, say, parabolic or spline curves. And that single feature can be a major time saver. It's pretty difficult to see on a finished guitar the difference between spherical, parabolic or spline and more difficult (I would contend) to hear it.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I use one from Tracy at Luthier Suppliers, a sponsor here. It is basically the same as the one David Ingalls showed. You can pick two radius when you order it.

Works great!!!

_________________
Joe Beaver
Maker of Sawdust

I was waiting for you to show up! I had to represent in your absence.


Sent from my iPhone using Tapatalk 2

_________________
http://www.CostaGuitars.com
PMoMC

One point not mentioned as yet is some folks preference to glue with planed vs sanded surfaces.
Sanding to radius on the dish then a pass with a plane would suffice.
I plane mine to a pencil marked radius per Mario's video - fast and simple on a shooting board.

Rob