Official Luthiers Forum!

G'day! I've built a number of OM's using the bracing layout off the OLF plan. I wasn't unhappy with any. I'm doing another and looking at the X, it looks pretty pinched at the lower bout. Like 87 degrees. I'm thinking it might benefit having it opened up somewhat. Just curious what others might use, as in how many degrees you have on the lower X of a 15" guitar?

Thanks pals!

Have you compared to the Grellier plan?

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I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

I tend to open the X up myself. Just be careful and make sure that your bridge wings fit over the x brace. Also plans tend to be over built. It's commonly recommended that you lighten up the specs on almost any plan.

depending on the time period the X brace angle originally was 99 degrees

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

My Antes OM plans measure 94.5, my StewMac 000 plans measure 95. The Kinkead plans (sort of an OM'sh thing) are 98. I've built several guitars at 95 degrees and are very happy with them.

I don't really measure the angle of the X. I open it to where the legs just cross under the tips of the bridge and keep the crossing of the X about an inch below the soundhole

It's like everything else, one thing affects the others. As you open the x angle and decrease long grain stiffness, you may gain some bass response, but at the price of some of the benefits long grain stiffness gives, punchiness, crispness, projection etc.

I think the angle definitely has an effect on the overall performance of the system, but it's still less important than top mass/stiffness, brace heigh etc. So any change you percieve will likely be fairly subtle rather than dramatic.

There's certainly no harm in finding out, especially since all the OLF plans tend to have a much tighter angle than most other designs. I know that I've used the external shapes unchanged, but I've changed the x angle so that the top end of the x's rested on the sides rather than butt against the UTB which makes me uncozy...

Following up to my earlier post, I’m measuring 101 degrees off the Grellier plans.

I’ve built 4 from those plans using different woods & scalloping or lack there of & they all have different character.

Sorry that I don’t have any advice since I’ve only built with the 101 angle but I do know that you can get a lot of variation with all the other variables. I’m trying to get my head around them before I start adjusting angles.

Kevin Looker

_________________
I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Thanks for the science lesson pal! Always refreshing from my seat of the pants approach. haha

That is one chunky plan for sure. I have to say that with 4 pages it's served me well over the years. My copy is pretty dog eared.

Are you bucking up for the Big Show next weekend?

Thanks Kevin! Pretty nice of that Grellier fellow to offer all those plans up for free. I've built a few L-00's from his plan and I think I'll do a couple more this winter.

And you're right. There's so many variables. I built a number of them with this 87 degree X. 2 using Redwood. Both buyers LOVED them. And they did sound great. Another is a buddies giging companion and I've heard him on stage with a few other guitars one time. He walked away from the pac, but he also opted for the best electronics

I'm trying to, we'll see. Everything is still in transit, in the works etc. down now not to days, but mere hours. Hurry postie, hurry!