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I'm building adjustable length rods to support the neck/tail blocks and inner curve of the waist. I was thinking of building them where I could leave them in place while glueing the top and back then removing them through the soundhole.

I was thinking of making teh rods 3 piece with the center section 1 ft long of 3/8" threaded rod. Don't won't to paint myself into a corner so I thought I would ask, how long of a rod can be removed through the soundhole on an OM? The soundhole is 3 3/4" diameter. Think I will be fine with the 12 in long piece of 3/8" threaded rod? Seems I should be but wanted to double check.

Per chance you have pics of what you use I would like to see them.

Thanks!

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Formerly known as Adaboy.......

Hmmm, I'm guessing I'm not explaining this very well.

Has anyone used some type of brace between the end blocks to keep them angled correctly while the top and back are glued in place? Then were you able to remove the brace through the sound hole after the glue set? I'm trying to decide how to design the "brace" so I can remove it through the soundhole after assembly. I'm curious how long I can leave a portion of the brace and still remove it. Seems 12" would work. I can test it on a dreadnaught, since I have one, but I don't have an OM or 000 to give it a whirl.

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Formerly known as Adaboy.......

I use turnbuckles to adjust my spreaders, just buy them in different lengths for the waist, lower bout, and end blocks.

I normally remove the spreaders once the top plate is glued to the rims, as I don't find the blocks or rims have a tendency to move after that. If the walls of your mold are square and the rims fit in the mold without having to force them to fit then I see no reason to use spreaders when closing the box.

Cal

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Remember, there are no stupid questions, only stupid answers!

I use a long turnbuckle with removable blocks at each end. On a dread I can get the 3 pieces out easy, the turnbuckle, and 2 blocks. On some smaller guitars I have to completely un screw one of the bolts out of the turnbuckle. I don't usually have a problem with my sides, and then rims fitting the mold but I've found that holding everything while I'm closing the box helps with fitting the neck. Do you glue the top on first? If you do just make sure you can remove the stuff through the sound hole before you install the back.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I too use blocks and turnbuckles .. all of mine can be removed thru the soundhole once the blocks come off the ends of the bolts. I use the eye bolt type, and simply use the drill press to 'chop' in a hole that the eye fits. Smaller guitars have different sized waist blocks, but the neck/tail blocks are small enough to come out of anything above 3.5 inch quite easily

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Appreciate your input.

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Formerly known as Adaboy.......

If in doubt, it's easy enough to do a trial run to see if the rod/s will come out okay....
I usually glue the back on first, with the spreaders in place, then remove them all prior to gluing the soundboard on.
Like Cal, I don't see any movement that requires the spreaders at that time.
I would say that If you find you sides are flexing still and you need spreaders to hold everything in place for the closing of the box, then you might want to reveiw your side bending method/s and make them fit the mold a bit better before gluing anything to them.

HTH,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Here's one setup, all from the hardware store, plus a block of maple. I found it awkward to have the turnbuckles I used to use crossing each other, preventing me from locating them where I wanted them.

The block will get trimmed down considerably once I find out what isn't needed. There are four separate pieces of all-thread, so they come out of the soundhole easily.



Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

Thanks again! And the pic is great Pat, neat idea.

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Formerly known as Adaboy.......