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Beau Hannam Ukuleles
09-28-2014, 08:19 AM
Here is the bracing i have used for this tenor guitar.
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SHAPE
As this is my first tenor guitar, I ordered both tenor guitar plans offered at Elderly Instruments as reference for general size and shape.
One plan is Ladder braced (no thanks). The better plan in every way shows the typical two lower tone bars beneath the X. (see the pic below)
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(This is the best plan- http://www.elderly.com/books/items/113-55.htm)

I changed the shape around using a combination of the plans, my Parlour guitar, 000 and LOO guitar shapes along with my trusty French curve. The Gibson Tenor guitar shape is my favourite (over the slightly clunky looking Martin 000'ish shape). Actually Gibson also used their L00 shape directly for some of their tenor guitars.

I stayed with the 23" scale, 14 frets to body. Sound hole is 82mm, which is a classical guitar size SH and the same as shown on the plans. I added a side sound port as a freebie for the customer as i'm that kinda guy.

TOP AND BRACING
Sinker redwood top is about 0.090-0.095""'ish but after binding I will thin the edges a touch more to bring out the monopole (know your poles). Bridge plate is .080"'ish Indian RW.

I transgressed from the plans again by using a bracing pattern consisting of a combination of X and 3 fan, all 1/4" wide. This type of bracing first came to my attention with Tony Mcmanus's PRS signature guitars and is inspired by Antonio Torres, a classical maker.
https://www.youtube.com/watch?v=YGRnUYRrsiA

I felt that the two lower tone bars (as found in the plans) would prove to be to stiff as every plan ive ever seen show braces that are ALWAYS to stiff- The Hana Lima plans are the same.

I have used this X and fan bracing on guitars before and it has proven to work very well giving more flex accross the grain which is needed in such an instrument as a tenor guitar or uke or classical guitar which don't have the string tension to drive a top in ways found on steel string guitar (long diapole, cross diapole). A uke is ALL about the monopole, across the grain vibration. You can only ask so much of so few inches (Hey Niq? :)

Fan Braces
I used 3, all of which slope down to nothing from a height of about 1/4" about 1" behind the bridge.

X Brace
I only scalloped the bass side of the X brace leaving the treble side a long slope- this is a building technique of Dana Bourgeois who is famous for his fine voicing of tops. I have done this before when voicing tops at Gilet Guitars in Sydney. If this technique proves to be a bit stiff for a Tenor guitar, it is quite easy (although annoying) to reach in the sound hole to scallop the treble side of the X after it is strung up.

Read this article:
http://www.pantheonguitars.com/voicing.htm

Watch these vids:
https://www.youtube.com/watch?v=O10hREMRufU
and
https://www.youtube.com/watch?v=bNchJIfT2O8

If your saying "all these links are about guitar tops, im not reading that", well, then you will never be a good luthier.

In another Tenor guitar thread, Aaron Keim mentioned that the tenor guitar should be approached with the view that it is a slightly larger baritone uke, rather then a small guitar. I agree, with the caveat that the difference between a slightly larger baritone uke and a small parlour guitar is only the use of steel strings on the later.

If their is much interest, i can take pics n measurements of brace heights etc.

I hope this all helps with your future builds (and mine).

SteveZ
09-28-2014, 09:08 AM
With that type of bracing, will it perform more like a classical (and accept nylon strings) or will it require steel?

Can't speak for anyone else, but as a TG affecionado would really appreciate any photos along the way.

Beau Hannam Ukuleles
09-28-2014, 09:20 AM
This one is built for steel strings- the bracing is a little bigger because of that but you could shave (say) 2mm off all braces and put nylon strings on it.- I'd have sanded to top thinner too for nylon strings- probably 0.075"-0.080"

Ill take some bracing pics tomorrow

here are a few more PICS from facebook
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rudy
09-29-2014, 02:47 AM
Thanks, Beau. I'll check out all the links and follow anything you post in this topic as I'm most likely going to eventually do a tenor guitar to my stable. Most of the tenors I've seen have too narrow of a board width, especially at the body join, for my liking.

Beau Hannam Ukuleles
09-29-2014, 04:24 AM
I'm going to stay with my normal uke neck dimensions which is
36mm nut
46mm 14th fret

I think that is reasonably close to the plans anyway

Tigershark
09-29-2014, 06:57 AM
I have some tenor guitars from the 1930's. The Gibson TG-00 and Martin 0-18T are both excellent sounding models. The Martin body is fairly shallow but still has good volume.

This is a 1933 Gibson. Two tonebars and a small maple bridge plate very close to the X brace.

http://s11.postimg.org/8sel5q9g3/P9130007.jpg

This is a 1930 Martin 0-18T. Look how thin the and scalloped the braces are. Since the body is smaller they use only a single tonebar and two cleats on the center seam. The bridge plate is also small and maple but much further back from the X brace crossing.

http://s13.postimg.org/byj842pon/P8100034.jpg

Weissenborn also made some tenor guitars in that time period, and the styling of them would be much more in line with traditional ukuleles. The bracing of those is different as well, but still based on an X pattern.

http://s22.postimg.org/qzrkqgush/KGr_Hq_RHJEMFF_P67lwg_BRe2h8s4_Q_60_57.jpg

Beau Hannam Ukuleles
09-30-2014, 04:25 AM
the bridge plate in that Gibson guitar is in the wrong place- those bridge pin holes are at the front of the plate!!! Strange, but as , like you said, it is so close to the x brace (also strange that it is THAT close) it probably all works fine.

Tigershark
09-30-2014, 06:16 AM
Gibson often misplaced bridge plates. I've seen it in both directions. A 1952 LG-2 with the pin holes drilled through the back edge of the bridge plate. And then others with the pin holes too close to the front edge.

Beau Hannam Ukuleles
10-01-2014, 04:48 AM
Good old Gibson... always there to screw things up. They accidentally made some pretty good instruments though.