Since the image uploader is fixed I thought I'd throw up this on how I cut lapjoints. I first saw this jig on Charlie Hoffmans site.
The jig for this took at least 5 minutes to make
and probably another 10 to adjust for the X angle I wanted.
Clamp it to the bench and measure the X braces and mark where the joint should be.
I use an 8mm router bit for dreds and larger and a 6mm bit for smaller OM/OOO type guitars.
Thickness your braces so that they are a little thicker than final dimensions.
Clamp your braces to the underside of the jig with another 'sacrificial' piece of wood to stop tearout.
Adjust your router to the appropriate depth and cut.
Next is to run the brace through the thickness sander to bring it down to final dimension and a tight fit.
Voila. Perfect joint.
This one is for an OM back brace @ 8mm
I know some people will find it quicker to do with a hand saw but this method is really foolproof considering the critical nature of this joint.
I also do a run of X braces while I've got the jig set up so there's about a years supply in the shed at the moment.
Cheers
Bob
