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I have come up with my first guitar design that is 100% my own. While the 2D design looks great to me on paper, I am about to actually start cutting into my good wood to make this thing. I am starting to get nervous that I have taken some things for granted or just plain didn't think of something important.

One thing that I do not know is whether my design would need a couple of degrees of back neck-angle to achieve good string action. According to the Tundra Man Online neck angle calculator, to determine neck angle you need the following values:

• Scale Length: 24.75"
• Fret Number Where Neck Joins Body: (I just arbitrarily chose 18, because that is where my ES335 joins)
• Height Of Fingerboard At The Neck Join: (.22")
• Height Of Bridge: (I bought a Schaller roller bridge and a Bigsby B5. It seems like I can raise and lower the bridge a good bit, how do I arrive at a fixed value for this?)
• Increase In Top Height From Neck To Bridge: 0 (this is a flat-top, guitar)

How does one determine where a neck "should" join the body of an electric guitar? And where do you even measure it? A Fender Strat, for example, joins at the 16th fret on the top of the neck, but then like the 20th fret on the treble side of the neck. (???)

Simple answer - No.

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"Act your age, not your shoe size" - Prince

Draw it all out from a side view.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

What Chris and Bryan said, but let me add that the neck geometry is the most important decision you will make in your design. Melvyn Hiscock has a pretty good chapter about it and it is the one thing that I futz with during the entire time I'm building a guitar.

First simple statement is that the neck to body joint has almost no affect on the geometry. It does affect a lot of other things - access to upper frets, strength of the joint you will be using, the whole way a guitar hangs on a strap. It has a minor affect on geometry in that at roughly the joint (actually more into the heel) the truss rod stops having any affect and there may be some transitions from relief to the fretboard extension. This is highly oversimplified but that little bump or hump or ski jump can cause all sorts of problems



My rule of thumb is that if the fret plane on my guitar just hits the top of the saddles at their lowest adjustable position I always get playable action and have enough adjustment to raise and lower the action as the guitar ages (or my playing style changes). That is a hold over from my acoustic building - I always want a straightedge on the frets to just hit the top of the bridge.

If you would like I can go thru the math but I always make a point of having the bridge I'm going to use in hand when I lay out the neck geometry.

Don't forget that there are two parts of neck geometry - the angle of the neck relative to the top and the amount that it stands proud of the top ("over stand"). The amount that the top is arched enters the picture. The scale length locates where the bridge is on the top but really doesn't factor into the calculations. I always assume that the saddle radius will match the fretboard so that can be taken out of the calcs too.

I'll give you an example - I recently fit a Kahler style bridge to a Jagstang style guitar. The Kahler wants to see the fretboard plane 1/2 inch off the top. The standard Jagstang bridge wants that to be 5/8 and the Warmoth body I had was routed that way. It took a half degree of shimming at the neck pocket to make the angle correct. For what it is worth the scale length is a short 24 inch and the body joint is at the 16th fret - those didn't matter. I routed for the bridge, put it all together and the setup is perfect.

Only rule I know is it must support the string tension so to me other factors are just as important. Take an SG for example.... very weak neck joints on these not so much from the 21-22 fret joint position but actually the pick up proximity to the joint limiting actual wood to carry the load. the thinner body also works against this joint for the same reason.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/