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Half Circle Cut on Bottom of Fretboard
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Author:  dubell [ Tue Oct 31, 2006 6:16 am ]
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Does anyone have a good way of cutting the half circle out of the bottom of a classical fretboard. This is to match the soundhole. The first time I did this was with a file. It took forever. I did an ok job, but I would like it have a "cleaner" look.

Thanks
Author:  Alain Desforges [ Tue Oct 31, 2006 6:32 am ]
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Doug, I made myself a 4 inch radiused sanding block. I drilled a hole in the middle and inserted a threaded bolt. I just attach this to my press drill. With 60 grit it does quick work.

Hope this helps.
Author:  Dave White [ Tue Oct 31, 2006 6:36 am ]
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Doug,

I use the same method as I use to cut the soundhole - with a laminate trimmer. I try and match the end of the fingerboard curve to the soundhole edge and my fingerboards are usually long enough that I can drill the hole for the pivot pin and make the cut (remember that the outside of the soundhole radius measurement goes to the outside edge of the router bit - and if you are binding the fingerboard akkow for this as well). I also cut from each edge and meet in the middle to avoid the router bit chipping the edges. Here's a couple of pics that should illustrate the technique:


Dave White39021.6101041667
Author:  Colin S [ Tue Oct 31, 2006 7:54 am ]
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Dave, you are a man of genius! First the modification to the binding attachment now this. I knew you had to be more than just a pretty face. (Surely something wrong there. Ed. Yes and stop calling me Shirley!)

Colin
Author:  Barry Daniels [ Tue Oct 31, 2006 8:17 am ]
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A sanding drum in a drill press is a simple way to tackle this job. Now I use my cheapo Sears oscillating drum sander. This allows you to sneak up on the line.
Author:  dubell [ Tue Oct 31, 2006 12:24 pm ]
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Dave,

I have the Stew-Mac Soundhole/Rosette Routing Jig as well. This is the first thing I thought of that I would like to use. Your photo helps out a lot as I have been wondering on how to line everything up.

The only thing is that I don't have enough length (waste material beyond the end of the fretboard) to put the pin in. What do you do in this situation?

Thanks
Author:  crazymanmichael [ Tue Oct 31, 2006 12:30 pm ]
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double stick it to a carrier board?
Author:  Rod True [ Tue Oct 31, 2006 12:36 pm ]
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Ya, what michael said. Use a carrier board with a shim where the router extension will site. Make sure it's the same height as the fretboard and your good to go..

I like to arch my fretboards the opposite way, and up till now just used the bandsaw and the disc sander, I like this idea though, I'll have to give it a try with a bridge overtop of the fretboard.
Author:  Joe Beaver [ Tue Oct 31, 2006 1:00 pm ]
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I just cut a circle out of 3/4 mdf or plywood, with my dremel circle cutter, the same diameter as the sound hole. Then glue sand paper to it and put a 3/8" bolt thru the center hole. Cut off the bolt head. Then just put it in a drill press and sand away. (cut the radius close on the end with a bandsaw or jigsaw first)

It's easy and 100% accurate.


WAIT....ALIAN JUST SAID THAT!!!!!! HE'S THE MAN..... Joe Beaver39021.8770717593
Author:  dubell [ Tue Oct 31, 2006 2:01 pm ]
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What is a carrier board??
Author:  crazymanmichael [ Tue Oct 31, 2006 2:04 pm ]
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a board you mount a workpiece to to hold it whilst you work on it. in the case mentioned above wherein the fb was not long enough to reach to the pivot point of the circle cutter, a carrier board would provide the needed length and hod the fb in position to cut the arc in the end.
Author:  Rod True [ Tue Oct 31, 2006 2:47 pm ]
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Doug a carrier board is also a board many people use to support thin pieces going through a thickness sander or a planer.

But in this instance, in Dave White's picture above, the white board which he clamps the fb to is the carrier board. Just think of his picture, with your fb clamped or double sided taped to the board and a second piece, the same thickness as your fb where Dave's long extension is. Than you drill your hole in the second piece that is the correct radius from the fb that you want to create.

Clear as mud?Rod True39021.9511458333
Author:  Alain Desforges [ Tue Oct 31, 2006 3:08 pm ]
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Dave, that is a great idea!

I have to try that for sure...
Author:  MSpencer [ Tue Oct 31, 2006 4:22 pm ]
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Very good ideas all around

Mike
Author:  dubell [ Tue Oct 31, 2006 11:23 pm ]
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Ok. I understand now. Thanks everyone.
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