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I'm building a guitar with a Dollin Adjustable neck joint and will be installing carbon fiber buttresses from the sides to top of the neck block. There will be carbon fiber in the fret board extension so the the extension will float and there will be two slots routed in the top for the carbon fiber to clear. So what I am wanting to know in this case how important is the UTB? Can I scallop the UTB say from where the slots for the fiber extension are to the ends to free up the top. Being that the extension is floating is the big UTB now needed? Is Rick Turner the one who's out front in this subject ?

If you are building in the style of Doolin, I'd suggest asking Doolin. Likewise Turner.

Three other comments:

Floating the extension does not change the compression and torque that the string pull exerts on the top, but it does concentrate them at the headblock.

I've scalloped either side of the UTB after topping it with .020" carbon fiber with no apparent ill effects on structure. Size of the UTB is about 3/4"x5/16" FWIW.

You are going where it becomes more art than science, unless you are a structural engineer and you can generate a good computer model.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Yes that's Doolin. I was thinking that the buttresses were to support the neck block from moving and compensate for the extra stress put on the top of the neck block being that the extension isn't glued to the top. I was thinking that the extension glued to the top transfered the stress to the top and across the transverse brace to the sides just like a load on a beam transfering the weight to the ground through columns. Maybe Rick Turner will chime in and give me some pointers. I haven't done anything with my UTB as yet and my CF rod will be here Monday so I'm just checking out what the possibilities might be. I was hoping some of you might be able to give me some direction here.
Howard, when you say topping the brace do you mean putting the CF between the top and the brace? Was the purpose of that to stiffen the UTB? If so wouldn't it be better to turn the CF vertical and laminate it in the center of the brace since that's what would give you the most strength. Inquiring minds want to know.

"You are going where it becomes more art than science"
That's fine with me. I'll go to where ever that road will lead me if it lets me build a good quality guitar.