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12-fret Dread - Scale Length & Bracing Layout
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Author:  George L [ Wed Dec 05, 2012 4:35 pm ]
Post subject:  12-fret Dread - Scale Length & Bracing Layout
I'm currently getting started on my fifth instrument. It's a 12-fret version of a Gibson J-45 featuring sinker redwood over Claro walnut. The plans I have were drawn up by Michael Collins (excellently done, BTW) and utilize a 24.75 scale length neck. I decided to try building this guitar after hearing a Bourgeois DS-260, which is his take on this configuration, but with a scale length of 25.5. Now, I'm not foolish enough to think I possess the skill to create anything quite that wonderful, but I thought it wouldn't hurt to consider this variable before affixing my top bracing.

Based on my calculations, accommodating the longer scale length would require moving the bridge patch and bridge back about 1/4", then adjusting the splay of the X-braces and repositioning the finger braces, so that everything intersects the same as it does on the original plans--only a bit further south.

However, I know just enough to be dangerous. So, I turn to my fellow OLFers for guidance. Am I missing something here? It wouldn't be the first time and probably not the last. One thing to note: I have already cut out the soundhole. Maybe that dictates staying with the shorter scale and leaving everything else alone? I don't know.

Thanks in advance,
Author:  bluescreek [ Wed Dec 05, 2012 5:36 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
a 12 fret dred can use the same scale length as the 14 fret .
Author:  George L [ Wed Dec 05, 2012 7:47 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
Thanks for the replies. I'm afraid I'm not experienced enough to clearly understand your comments, so I'm going to take this as a sign that I should stick with the short scale neck and build the guitar using the plans I have in front of me. I make enough mistakes as it is. Complicating things for myself would not be a good idea. I thought this might be the case and now I'm certain of it. Thanks again for your replies.
Author:  Jeff Highland [ Wed Dec 05, 2012 9:17 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
Is the plan you have for a 12 fret neck join? J45s were always 14th fret, that is the major question.
Scale length change is not a big deal just moving it south.

edit
I see that michael has a modified plan for 12 fret
In this case, if it is drawn up for a true 24.75" scale, not one of the gibson versions referred to as that,but actually shorter, then the bridge will be moved by 25.5 minus 24.75 divided by 2. Therefore 0.375 " or 3/8"
Author:  nyazzip [ Wed Dec 05, 2012 9:38 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
Quote:
Therefore 0.375 " or 3/8"


....or, 9.5mm!
8-)
Author:  George L [ Wed Dec 05, 2012 10:02 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
Quote:
I see that michael has a modified plan for 12 fret. In this case, if it is drawn up for a true 24.75" scale, not one of the gibson versions referred to as that,but actually shorter, then the bridge will be moved by 25.5 minus 24.75 divided by 2. Therefore 0.375 " or 3/8"


Yep, that's the version I have. Really nice plans and I have things all set up to glue together as drawn. I got to thinking (always risky) and wondered if I could just slide the bridge and related bracing south by the scale length difference. I think that would work. However, I have already cut the soundhole and I'm not sure if leaving that where it is and moving everything else would be a mistake. Perhaps there is some magical distance from X-brace intersection to center of soundhole that creates optimal tone? I just don't know enough about these things to start improvising without adult supervision. :-) I've pretty much decided to forget all this and move forward as is, but it would be cool to know if my thinking is correct (or not).

Thanks,
Author:  TRein [ Thu Dec 06, 2012 8:13 am ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
Do a quick search on "Roy Smeck Stage Deluxe" and you should turn up some images of Smeck bracing and pics of the Scipio blueprint of a Smeck Deluxe. Coupled with the plans you already have you should be able to get an idea regarding brace layout and angles. The Smecks and Radio Grandes were braced a bit more sturdily since the Hawaiian guitars of the day were pitched higher and had more tension. The Stage Deluxe and Radio Grande are the 12-fret versions of a J-45. I wish the Scipio plans were still available but they are out of print.
Author:  SteveSmith [ Thu Dec 06, 2012 10:46 am ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
I built my second with a short scale from long scale plans (the other direction) and the difference was about 1/4" - it was not that hard to do. The neck length/body join/soundhole relationship needs to be worked out. I taped a 4 foot piece of freezer paper to the bench and started laying things out to make sure the spacing worked and then just built the thing. I wouldn't hesitate to modify the J45 for a long scale if I wanted to and I'm not that experienced; I'm working on #5 right now.
Author:  theguitarwhisperer [ Thu Dec 06, 2012 12:22 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
You can leave the soundhole in the same spot and still make it a long scale. You'll just have to trim your fretboard to fit. You may lose a fret but that's no big deal.
Author:  Jeff Highland [ Thu Dec 06, 2012 2:06 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
You have cut the soundhole, but have you cut the soundboard perimeter to final size?
You may have a bit of wiggle room there.
Author:  George L [ Thu Dec 06, 2012 2:27 pm ]
Post subject:  Re: 12-fret Dread - Scale Length & Bracing Layout
Thanks again for the replies. I have indeed trimmed my soundboard to within 1/16" of it's final size, so not enough wiggle room there to help me. I appreciate the input and am still pondering this scenario, although I do think I will stick with the shorter scale. There are enough hurdles for me to clear as it is. This is a terrific hobby for me, as it forces me to learn new things all the time, to think differently, and to practice a level of patience that I rarely employ in other areas of my life.
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