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Placement of bridge plate help
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Author:  Jeremy Douglas [ Mon Jul 14, 2008 9:21 pm ]
Post subject:  Placement of bridge plate help
I'm building a LMI dread kit(25.4 scale length) and I noticed when drawing out the bracing pattern on the top today that the bridge in the plans is a different size than the bridge supplied. This probably wouldn't matter if I used a gigantic bridge plate like the one shown in the plans but I wanted to use one that was only 1/8" longer than the front and back of the bridge.

I think I know how to find the bridge and bridge plate location to mark it on the underside of the top but I thought I'd run it by you guys first...

The only known fret location on the plans or soundboard is the 14th fret so I have work off that. I can find the location of the saddle slot by subtracting the distance from the nut to the 14th (14.0856" in this case) from the total scale length(25.4"). This distance(11.3144") plus the compensation (7/64"?) will give me the distance from the 14th fret location on soundboard to the location of the center of the saddle slot(11.4238"). Then to find the front of the bridge measure on my actual bridge from the center of the saddle slot to the front of the bridge and transfer that to the soundboard. Then to locate the front of the bridge plate add 1/8" to the front of the bridge location.

Is this right? It sure seems right on paper but since I just figured all this out on my own my brain is starting to overheat and I need to take a break.

Thanks, Jeremy
Author:  Terence Kennedy [ Mon Jul 14, 2008 10:18 pm ]
Post subject:  Re: Placement of bridge plate help
If I am reading it right that sounds pretty good Jeremy. You can also set your pre-slotted fretboard on the top and line the 14th fret up with the location where the top will join the rim. Take the distance from the nut to the 12th fret and transpose it( plus compensation) from the 12th to find the location of the saddle on the soundboard. When I took the Fox course we were taught how to make a "core template". Simply a piece of heavy posterboard that is cut to represent the total scale length of the instrument. You mark the locations of the 12th and 14th frets, the soundhole, and the scale length as well as the compensated scale length. You can also mark the front of the bridge on the same template. Lay it on the top centerline and put the 14th fret (the diamond cutout) over the marked spot where the top will join the rim. If you plan to build more guitars they are very handy to have. I have one for each scale length.
Terry

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Author:  Jody [ Mon Jul 14, 2008 10:19 pm ]
Post subject:  Re: Placement of bridge plate help
i just went through this to correct an error of a badly layed out top, which was supplied in a kit. I realy dont trust the plans to the preciseness required for a guitar. and the math .. well it should work on a paper but ..... what I did , and you can to , to double check your math is I laid out an already slotted fet board , 14 th fret to the body , then measured from the twelth fret to the nut, then from the twelth fret back to the bridge location and marked the top, it all worked out for me that way ! Jody
Author:  Flori F. [ Mon Jul 14, 2008 11:07 pm ]
Post subject:  Re: Placement of bridge plate help
I'm a novice, but I have to ask why you're interested in a small bridge plate? Are you concerned with bass response? As you're building a dread, that really shouldn't be a problem, no?

I've heard horror stories about undersized bridge plates...

My apologies if I'm being dense.
Author:  Jeremy Douglas [ Tue Jul 15, 2008 7:16 am ]
Post subject:  Re: Placement of bridge plate help
Thanks Terence and Jody, I'll be sure to double check my math before I drawout the bridge location.

mffinla, I'm concerned with repsonse in general. From my understanding 1/8" on each side of the bridge is pretty common. I don't think anyone builds guitars with the massive 70's Martin style bridge plate anymore.
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