TD's Acoustic (FH-5V)

[Trevor Davies]

Trying to determine the neck angle for this build. After stabilizing the arched guitar, placing a straight edge from the assumed fretboard height at the top of the body and the lowest height of the bridge, I measure an angle of about 5 degrees!

[Trevor Davies]

I have made a 12mm mdf jig to help route out the first parts of neck pocket, and a base to stabilize the body. I have routed out the top pattern and the side/front pattern

My router won't get much deeper than 20 mm with the jig in place.

Next, I will drill out the rest, using a jig to get the 5 degree angle.

Slowly getting there!

[fender3x]

Nice looking jig! I wondered if you were going to put the angle in using the jig. 5 degrees seems like a lot! Nice that you have an adjustable bridge, in any case to give a margin of error.

[Trevor Davies]

Drilled out the as much wood as possible using a portable drill press angled at about 4 degrees (I decided on 4 degrees as I can shim to make a larger neck angle if necessary) with Forstner drill bits. After removing most of the wood I went "old school" with a chisel and mallet! All went OK. Lots of sanding and the neck now fits.

I think the fretboard is still a bit too high! If I lower the neck further, I will probably need a greater angle!

[fender3x]

I wonder if you could clamp the neck, add the trapeze and see how much the string tension draws the neck up? If that is impractical...(or just plain won't work) you could take an acoustic with a similar scale, measure the difference without string tension and with string tension to see how much it lifts.

[Trevor Davies]

Thanks, fender3x. I will give this a go when I'm happy with the neck seated in the neck pocket.

I'm still not sure if I should have the fretboard sitting lower to the deck!

So, I have been procrastinating doing other work.

I did manage to make a small sanding block on a stick to help with the sanding of the neck pocket. I designed it so that it takes a piece of sandpaper the width of the roll, and about 1 inch wide. It worked well.

[fender3x]

That looks like a TD jig to me. Functional, of course. Perfectly curved clamping surface. Recessed screw. Ready for the Stew Mac scouts ;-)

On the other topic. The nice thing about an adjustable bridge is it gives you some room for error, but mostly at the high end. I took a look at a book in my Google Books library: The Phoenix Guitar Company's Guide to Guitar Making, by George Leach (2015), Wheatmark: Tucson, AZ. They recommend leaving 3/4" between the plane of the fretboard (measured with a straight edge) and the body of the guitar where the bridge goes. They were using an adjustable wooden bridge (not a TOM), although I don't think a TOM would make much difference. This was for an L5 type with a pickup mounted in the body. For a pickup on top they recommend leaving a little more (1"). If you have access to the book, you might find their fitting technique helpful. I know I would, but I also think I lack your woodworking skill, so maybe you don't need it! ;-)

Not sure if this helps, but these are more accessible numbers than my other idea... Which was to see if I could convince a friend with a similar guitar to take the strings off, flatten the truss rod and take the measurement on his guitar. That might take a while. Even with the current climate variability not sure when those arctic currents will reach the inferno.