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I would like to use a cumpiano neck joint and my questions are how wide and deep is the tenon? Also how big do I make my neck block and should I make it out of maple since the neck & guitar body is maple?

Thanks, John

As no-one has jumped in here I will I'm only on number 1, but used this joint. The mortice is still exactly the same as in the book, 3/4" wide 1" deep, wood for the neck block in my opinion us almost irrelevant mahogany is used as it's strong and light really I used oak and I had some, I've repaired guitars with softwood neck blocks too though I wouldn't recommend it. The joint has to be good though mine creaks a little as it wasn't perfect, but it was hand cut I'd rout it now. I take it your familiar with his site?

http://www.cumpiano.com/Home/Articles/S ... block.html

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Formerly JJH

I learn more from my mistakes than my successes

You'all know that Cumpiano has abandoned that joint for barrel bolts now, don't you?

Do you mean like this?

I can't really make out the fasteners in that photo, Mark.

Try this pic.I have locateing studs in the tenon in the pic to locate where to drill the neck block for the bolts.

I am not sure how you entire assembly is going together but typically scoket head bolts are used rather than studs. But you may just be using the pointed studs to mark your drill holes in your neck block but anyway here is a cross section detail of my version of the Compaino neck joint.



I also don't know how thick your neck block is but on the length of your tenon an mortise but mine tenon is .6875" and my mortise is .750" deep leaving me 1/16" of clearance between the mortise depth and end of tenon and .50" of wall thickness to support my bolting

I have the plans for the Cumpiano guitar from the book with the barrel nut neck system. Drawn by a J.G.Moore. The tenon on the plans is 13/16" wide and 1" long. Mine is 3/4" wide and just over 3/4" long. Height top to bottom is determined by the height of the head block. I use 10mm barrel nuts from Ace hardware as the hole is centered on them. They are just a little over 3/4" wide so I file the ends a little. I drill a 3/8" hole and enlarge with a reamer for a snug fit.
Terry

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I do use the allen bolts.Here is a pic of mine.My tenon is 3/4" wide and 1" deep.The mortice is 1/16" deeper than my tenon for adjustment.