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I'd like to get some feedback on these plans before moving forward.




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It's a 27.5 to 25.7" Baritone OM. Usually use one tone bar and one finger brace on each side for my standard OM's. The tops are very stiff, very tight grain Adirondack Spruce.

I would move the shorter leg of the X brace so it would end on the side closer to the mid point of the soundhole. That would take it further out on the wing of the bridge (but still on it) and move the crossing point of the X closer to the soundhole.
I like the wings of the bridge to catch the X brace, but not by a whole lot. I think having the X too close to the string saddle makes for a tight sounding guitar. YMMV

What Clay said.

Steve

The bass side upper X leg is way too low. Not going to function structurally like an X brace. It needs to intersect the perimeter as close to the upper transverse brace as possible. The bigger the gap, the stronger the soundhole brace on that side needs to be. Even the upper treble leg is a bit on the low side.

It's ok if the X intersection moves off the centerline some. I like to keep it as close as possible, but can scoot it a bit to improve other things.

Your tone bar is backward compared to normal, but that's a fair choice.

Bridge shape can be manipulated to allow for easier bracing. Specifically, the farther forward you can get the bass wing, the less the X needs to be rotated. Reduce the angle of the front edge of the bridge. Twist the wings for a more S-shaped bridge. Note that a standard bridge already has an angled saddle compared to the front edge of the bridge.

FWIW, I don't see the need to make the x bracing asymmetrical. Look at the unsupported area north of the x brace on the bass side.
I think you could leave the x-braces symmetrical, shorten/reshape the treble wing of the bridge , and bring the tone-bar over to the treble side, tucking it up against a bridge plate (not shown)
25.7 treble side is not much more than normal for an OM (1/3"), so you would just need to extend/reshape your normal BP to support the bridge mostly towards the bass side.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Thanks for the input guys. The center of the X-Brace is .49" off center. I had put too much stock into that earlier. Here's where I'm at now.


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Much better. As Colin says, do extend the bridge plate to support that pointy bridge corner.

Oh, and make sure you're working with the intonated saddle position and not the pure scale length numbers. Hard to judge just by looking, but the saddle angle doesn't look quite enough considering how extreme the nut angle is.

Thanks, the saddle angle is based off the pure scale length numbers to the middle of the saddle. The saddle is .25" thick so there is room to adjust but I may as well dial it in as much as possible. Where or how can I find the distances for a compensated sadlle on this particluar scale?

That looks like it's shaping up nicely.
I used the SM fret calculator for the short/long scales and just applied them to the individual 1st/6th strings for my fan fret - straight lined the rest, worked out fine with a 3 mm saddle, although I had much less difference in scale lengths.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Thanks Colin, I'm hoping to get it wrapped up, plotted and hung today.

What about pointing the finger furthest to the left more toward the point of the saddle and tucking it under the X brace to catch the corner? Bad idea? I do like the symmetrical look but obviously the integrity of the instrument is more important.

I like it! (not that that matters) It looks like a sensible modification to a successful classic design.

Heres the final two versions unless anyone sees something that needs to be addressed. The second one hasn't been posted as its similar just more conservative. Tentatively ready to start bracing later today. For now....bed time!


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http://www.mullinguitars.com/2015/10/compensation-calculator-for-steel-string-guitars.html


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My observation would be that your scale lengths are quite short for a baritone. I suspect it wouldn’t hold up tonally below C#c# or at best Cc. I like baris with long scale lengths that allow them to be tuned waaay down, to at least B to b, but preferably A to a. That’s where things really get seismic. With a 29” scale length, you can easily achieve Aa tuning without the low notes turning to mush. Even alternate tunings based out of A are possible. And the strings get so supple due to the lower string tension that it’s really a joy to play.


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Mountain Song Guitars www.mountainsongguitars.com

Why put the saddle at a different angle than the front angle of the bridge?


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I think this approach works well for a guitar in “standard” E-e tuning and string gauges. Larger strings and dropped tuning will throw the SM calculator out-of-whack, and 3 mm is definitely too narrow to intonate a baritone unless you split the saddle (cf. Lowden).



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Ken is pointing out that there are really no “standards” or “accepted” dimensions when it comes to baritones. This dance between playability, timbre, tone and musicality is something we fiddle with and, for me at any rate, ideas on the sweet spot are constantly evolving as I build and play, and as I get player feedback. That’s part of what make this niche exciting for me as a builder.


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You will, I hope, remember to flip that pattern over before using it to brace the UNDERSIDE of your top!


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Sorry to go off-topic but those are great looking drawings. What software are you using?

I was trying to keep the ends of the bridge one the X's without getting too far off of the centerline.

I'll keep that in mind for the next model, which will be closer to a SJ or Jumbo. 29"-27.5"? Indeed alternate tunings is behind the motivation here but I most often play in dropped D tunings like DADGAD and other variations. My OM body is only 19.5" long so 29" might have been a bit much for the neck blanks I have on hand at the moment. A 29" scale is interesting, thanks for the suggestion.

Indeed. I have seperate prints for templates that I cut everything out with a razor blade. I used to then transfer it to Masonite but the paper I use now is so thick that it's not necessary.

Thank You. I use AutoCAD Map 3D which I also use for my full time job. You could easily use AutoCAD LT as well as it's much cheaper and does all the same 2D stuff that Map 3D does just as well. They offer free 30 day trials so it's worth checking out. I've also used Adobe Illustrator with good results as well, that's the cheapest and most user friendly option at least from my view. CAD learning curve can be steep but it depends on the person and your level of comfort with design software. I have a 3D animation background so learning CAD was pretty straight forward for me. There's a lot of free tutorials on YouTube if you do go that route. Lynda.com is also a priceless resource for learning new software- well worth the $30-ish/month I'm my opinion. Both Illustrator and CAD can also import vectors into Aspire or Fusion 360 as well if you have access to CNC, so that's another added benefit.

Last revision looks good to me

And for vector drawing, Inkscape is free and does everything you need for guitar plans. Save as .pdf for printing at Kinko's.