Guitar #3 -- an OM cutaway
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Diane Kauffmds
- Posts: 3252
- Joined: Sun Mar 09, 2014 8:13 pm
Re: Guitar #3 -- an OM cutaway
You're coming along. It's looking good.
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MaineGeezer
- Posts: 1714
- Joined: Wed Aug 13, 2014 12:14 pm
Braces are on the top....
I've got all the braces glued to the top and I'm well into the thinning-down and shaping process, although some of them are probably still a bit too thick and I still need to scallop them. I also want to get Carter's opinion of the bridge plate, which isn't glued in yet.
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Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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MaineGeezer
- Posts: 1714
- Joined: Wed Aug 13, 2014 12:14 pm
Binding on the back
I've got the binding on the back. I cut the groove primarily with a gramil, which was a long process. It came out fairly well. I then made a light finishing pass with my Dremel.
Despite great effort when gluing, I ended up with a few gaps. I hope I can fill the gaps in such a way that the are less noticable.
Despite great effort when gluing, I ended up with a few gaps. I hope I can fill the gaps in such a way that the are less noticable.
You do not have the required permissions to view the files attached to this post.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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MaineGeezer
- Posts: 1714
- Joined: Wed Aug 13, 2014 12:14 pm
Regress before progress.....
After looking at the back binding some more, I decided the bass side binding was bad enough to warrant doing over. It was not a complete loss. It was an opportunity to find out how difficult it was to un-glue something that was glued with fish glue, something I had been wondering about.
It turned out to be quite easy. A heat gun and a thin spatula peeled the binding loose in a few minutes.
Anyway, I put on a new piece of binding, which came out much better. (Fewer gaps and more uniform thickness after sanding.)
I've also scalloped the braces. They need a bit more tweaking, which Carter will help me with when we "voice" the top. Or rather,when Carter voices the top and attempts to explain to me exactly what he is hearing as he taps, and what should be done to the top because of it. After two previous tops, I still have only minimal ability to do it myself. Maybe some faint glimmer of understanding will penetrate my skull this time around.
It turned out to be quite easy. A heat gun and a thin spatula peeled the binding loose in a few minutes.
Anyway, I put on a new piece of binding, which came out much better. (Fewer gaps and more uniform thickness after sanding.)
I've also scalloped the braces. They need a bit more tweaking, which Carter will help me with when we "voice" the top. Or rather,when Carter voices the top and attempts to explain to me exactly what he is hearing as he taps, and what should be done to the top because of it. After two previous tops, I still have only minimal ability to do it myself. Maybe some faint glimmer of understanding will penetrate my skull this time around.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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MaineGeezer
- Posts: 1714
- Joined: Wed Aug 13, 2014 12:14 pm
I hate it when this happens
I was making the bridge the other day. Things were going well...until they didn't.
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Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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MaineGeezer
- Posts: 1714
- Joined: Wed Aug 13, 2014 12:14 pm
The 2nd attempt was more successful
The 2nd attempt came out well.
You do not have the required permissions to view the files attached to this post.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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Kevin Sjostrand
- Posts: 3718
- Joined: Sat Feb 09, 2008 8:06 pm
- Location: Visalia, CA
Re: Guitar #3 -- an OM cutaway
Looks like your oops bridge was replaced with a very nice bridge. Looks great.
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ruby@magpage.com
- Posts: 1564
- Joined: Thu May 24, 2012 8:03 am
- Location: Chestertown Maryland
Re: Guitar #3 -- an OM cutaway
I think that if you made the other wing of the oops bridge look like the one sticking up, you could start a trend. The second bridge looks great
Ed
Ed
Ed M
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MaineGeezer
- Posts: 1714
- Joined: Wed Aug 13, 2014 12:14 pm
Cutting the top binding channel, and the Theory of Voicing
The top has been "voiced" and glued to the sides, so I now have a closed box.
Here's the Theory of Voicing (sort of). I wouldn't be surprised to learn that there are those who think this is totally wrong and the exact opposite is correct...but anyway, here is the theory according to Carter, which he learned from Dana Bourgeois, filtered through my faulty memory.
When you tap the top, you want to hear a pure tone (ideally a single frequency), not a complex tone made up of multiple frequencies that are competing with each other and cancelling each other out, which can diminish the sustain period and also cause varying amplitude as the various frequencies reinforce and cancel each other out as their phase relationship changes over time.
You can change the pitch by selectively shaving the braces. The braces are scalloped, and by thinning the ends you will raise the pitch, and by lengthening the thinned center section you will decrease the pitch. I think I've got that right. Carter says it's analogous to tuning a wood marimba key. If the key is sharp you remove wood from the center, and if it's flat you trim a little off the end.
To know which brace to shave, tap the top over that brace and listen to the response. When you hold the top, try holding it in different places until you find a place (or more than one place) that is a "node," i.e. essentially a dead spot where the top is not vibrating. Holding the top there lets the rest of the top vibrate freely because you are causing minimal damping.
Or something like that.
With the top glued on, I've started cutting the binding and purfling channels around the top. As with the back, I'm starting out with a gramil and chisel, doing it by hand. It's very meditative. I may yet resort to a router as i did on the back to do a final cleanup pass.
Here's the Theory of Voicing (sort of). I wouldn't be surprised to learn that there are those who think this is totally wrong and the exact opposite is correct...but anyway, here is the theory according to Carter, which he learned from Dana Bourgeois, filtered through my faulty memory.
When you tap the top, you want to hear a pure tone (ideally a single frequency), not a complex tone made up of multiple frequencies that are competing with each other and cancelling each other out, which can diminish the sustain period and also cause varying amplitude as the various frequencies reinforce and cancel each other out as their phase relationship changes over time.
You can change the pitch by selectively shaving the braces. The braces are scalloped, and by thinning the ends you will raise the pitch, and by lengthening the thinned center section you will decrease the pitch. I think I've got that right. Carter says it's analogous to tuning a wood marimba key. If the key is sharp you remove wood from the center, and if it's flat you trim a little off the end.
To know which brace to shave, tap the top over that brace and listen to the response. When you hold the top, try holding it in different places until you find a place (or more than one place) that is a "node," i.e. essentially a dead spot where the top is not vibrating. Holding the top there lets the rest of the top vibrate freely because you are causing minimal damping.
Or something like that.
With the top glued on, I've started cutting the binding and purfling channels around the top. As with the back, I'm starting out with a gramil and chisel, doing it by hand. It's very meditative. I may yet resort to a router as i did on the back to do a final cleanup pass.
You do not have the required permissions to view the files attached to this post.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
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MaineGeezer
- Posts: 1714
- Joined: Wed Aug 13, 2014 12:14 pm
Re: Guitar #3 -- an OM cutaway
The binding and purfling around the top came out quite well. Cutting the channels by hand with a gramil and chisel took a while, but it wasn't as difficult as I anticipated.
You do not have the required permissions to view the files attached to this post.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion