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Ok, me post picture or something. We'll go to 'visual' mode and use .ooX gauges. - Im using HHG now, maybe that was an issue. I just slapped as much on as possible for one side (id rather do both but the time issue.) Noticed that #@#@@)__@(# the dang brace was tilted to the 'left'. Had to take off and do over.

A go bar rods forces will not all be taken in the pure vertical at the ends. There are side forces at work. This is obvious just as a bow and arrow work. When the bow straitens out, it propels the arrow in the same direction as the curve righting itself. The force is the same idea for a gobar. This can cause problems with glue up. No doubt.

Im talking measureing with the gauges here. I try for .002 before glue- up. Less than that is difficult for me using 150 grit and given wood variation. 

 

If your not careful where you place gobar rods, you may end up with uneven joint/surface cohesion. At least Im pretty sure of it.

 

Glue- up is anther issue. Its common with wood working to glue BOTH surfaces. Not sure why critical strength joints in the guitar would be less critical than furniture joints. Im not an expert, so I cant tell you why, but rules is rules.

 

I disagree about side pressure with gobars. There just isn't any. The analogy of the archer's bow is not relevant here as we do not attach the end of the gobars to a string and then apply force with our arms. For a gobar to have a sideways force, there would have to be an equal and opposite force applied to the gobar, but last time I looked, nothing is pushing my gobars in that opposite direction. There is only force on each end of the gobar (from the deck and work table) that is completely vertical (one up and one down) that cancel each other out. Basic engineering statics here.

Ok Todd, thanks,

 

maybe my gobars are not "in line",and thats what causes unequal pressure. No one said you need a plumb-bob to glue up braces.

I'm still making the spring ones.  I actually spent tonight making 1/2" dowells be 15/32" so they fit smoothly into CPVC pipe.  Seems to work just fine.

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Waddy

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What kind/size of springs? Do you get them at Ace hardware?

I got them at a local Hdw company here in Charlotte, called Little Hardware.  What I liked was that they were about 5" long, small enough in diameter to fit in a CPVC 1/2" pipe, have a fairly even compression rate, that gives me a range of from 5 - 9 lbs in the last 1 1/2" of compression, with 7 being right in the middle of that,.  I posted a picture before, of my prototype, here it is again.  You can see the springs just above the prototype Go-bar.



I went out to the shop and checked to see of the package was labeled. The springs are "AJAX Springs" - Part # 54, maybe you can find them on the internet.  It took me a long time to find what I was looking for, and I couldn't order them because I couldn't figure out what would work and not work with the specs I could find on line.  I paid like $1.50 each for the first 8 or so, then I ordered 15 from them, and they gave me 3 packs of 6 and they ended up costing me about $0.75 each.  If you want to try one, I'll send you one and you can play with it to see if it will work for you.  PM me if you want me to do that.

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Waddy

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Sound Clips of most of my guitars

Another thing, the Charlotte Pipe CPVC doesn't work as well as Genova.  It is a little smaller ID, and doesn't stay as straight.  The difference is enough that the spring is just too tight to work.  Also, you'll have to resize the 1/2" dowel rod.  I had some cold rolled steel 1/4" thick, and drilled a 12" hole until the bit had cut almost all the way through, leaving only about a 3/16 edge around the inside.  I then drilled that out with a 15/32 bit, leaving a thin lip around the edge.  Then I filed surface where the bits cut through flat with a fine file, leaving a sharp edge on a 15/32 sized hole.  Driving the dowel through from the bottom as it was drilled, scrapes off the excess, and the 1/2" back cut below allows for clearance as the dowell comes past the sharp edge.  It takes a while to do a bunch of them, but it works.  I got some tearout, but was able to sand it out pretty well.  They don't need to be perfect, just small enought to slide freely in the pipe, and big enough to not fit inside the spring.

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Waddy

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 drilled a 12" hole until the bit had cut almost all the way through

Should read - drilled a 1/2" hole, not 12 inch hole

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars