Checking Neck Angle

[naccoachbob]

I'm sure this is going to be obvious to most folks who are building guitars, but my perception of the obvious went haywire on this.

I have used a bevel gauge a number of times before, and so I would use one to get the angle of my side to top at the neck joint. I would put the wooden end against the side, and the sliding metal part along the top, and tighten it down. Just like here in the first picture.



But, when I went to check the complementary angle from my fretboard/neck to the neck heel, I would try doing it like in the next picture.



Impossible to get the metal part to sit on the fretboard/neck and get an accurate reading on the heel, much less mark the heel appropriately.
Well, today I stopped at Steve Kinnaird's shop on my way back to my office. Steve has been a mentor for me since I first started making guitars from kits, maybe 4-5 yrs ago. He's a very accomplished Luthier and has always been there when I needed help. I mentioned that I was using a dovetail joint, but that I was very interested in how he and his co-worker, Ryan Middlebrook, do their neck heels. They use butt joints. And the talk went to neck angle as well. So Ryan showed me how they used the bevel gauge. Here's his method in the 3rd pic.




And here's where my "oh crap" moment came. Ryan put the wooden part of the gauge on the fretboard/neck, and the opposite side of the metal part along the neck heel. At first, I got more confused looking at what he'd done, but then finally had the "DUH" moment where I saw it.
I hope others have it together better than I did on this thing. I can't help but laugh - it's not the dumbest I've ever felt, but it's in the top 10!
Happy building, everyone.

[ruby@magpage.com]

What's the difference - I'm not seeing it?

Ed Minch

[Darryl Young]

Something to think about.

While this procedure will achieve a good fit of the neck to the body and a good fit of the fretboard extension to the soundboard........it does NOT insure you have the correct neck angle for proper string height at the bridge. You could have a great neck fit and the action be high/low unless somehow you've previously determined that the angle of the upper bout is perfect for your target string height at the bridge.

[naccoachbob]

What's the difference - I'm not seeing it?

Ed Minch

Ed, the 2nd and 3rd picture are different. In the 2nd picture, the steel leg is on the fretboard, but it is centered to the wooden leg. So it's almost impossible to hold it to the fretboard. It has to be angled sideways so that the wooden leg will align with the heel. By flipping the two legs and having the wooden leg on the fretboard, the centered steel leg will run alongside the heel in case the heel needs marked and/or chiseled to it's correct angle. The angle formed between the two is the same, no matter which leg goes where. It's just that physically it's easier to have the wooden leg on the fretboard. That was my only point. I had it in my thick head that I had to fit the bevel gauge to the neck in the same way I fit it to the body - not changing the orientation.

Darryl, I agree, if the body wasn't built right, none of this matters.

[ruby@magpage.com]

I came up with a way to make sure things go together with minimal fuss. I am sure that after I get some confidence I won't need to do this, but for now, it is a big confidence builder. I take my biggest bevel gauge and set the angle on the neck, then I do this:

(I hope the pictures don't get to you last first instead of first first)

There is one more photo in the next post

[ruby@magpage.com]

Yep - looks like the third one should be first and the first one should be third. Here is the last one

[ruby@magpage.com]

And I forgot to say that you can make a perfectly serviceable bevel gauge with 2 straight edged pieces of wood and a small C clamp. And you easily get complimentary angles by taking the angle off the neck, drawing that on a piece of plywood with the handle on a straight edge, then resetting the gauge on the line with the handle on the other side.

Ed Minch

[Tom West]

Darryl has hit the nail on the head. The neck angle problem has to be worked out in the building of the box or a compromise may have to be accepted if we fail to do so. John Hall has preached this and has video about it in his you tube set.
Tom