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Hello,

I hope everyone is doing well and working from home or self-quarantined (aka shop time)!

I'm working on a Tenor uke, its been a while since I have built a Uke. I'm having fun with it.

I have a question about neck angle. First, some details about what I'm building.

- 17" scale length
- 14 fret to the body
- 0.125" x 0.325" carbon fiber rod as "truss rod"
- Top radius is 30' with upper bout sanded flat
- UTB put on flat
- Mahogany neck
- Bolt on M&T

When building guitars I started with the Robbie O'Brien video lessons and he recommended setting the angle so that there was a 3.5mm gap at the bridge location when projecting the neck plane (no fingerboard yet) out to the bridge location. At the time I didn't fully understand what we were doing there and just following directions. At that time I was using a home made jig I built from watching Robbie's YouTube assembly video. This worked fine.

After 5 or so instruments I picked up the LuthierTool jig which is great and I had a much better feel for what the neck angle geometry should be for guitars and why Robbie used 3.5mm. I've adjusted to better match my building style and the types of guitars I'm building, but overall it is clear how the angle chosen here affects the rest of the build process.

Now on to Uke... Should the Uke neck just be put on flat or is there a recommended "projection at the bridge" measurement?

Brad

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My daughter does a uke camp for girls 10-14 each summer and she uses S-M uke kits. They are Soprano ukes, but everything is flat and 90°. I built a soprano and used that formula with success.

Ed M

It all depends on your bridge heigth and saddle protusion.
You want about 2.5 -3 mm string clearance (action) at fret 12.

Thanks to you both. The way I’m thinking about it is - if I use the LuthierTool jig and set the angle back so the dial indicator is 0, then I’ll be good.

The fretboard, bridge height and saddle are all still variables I can control. The fret height is constant.

If the jig is zeroed then the bridge + saddle height just has to be fretboard + fret height + .180. That will give me 0.090 at the 12th.

I guess what’s throwing me is do I need to at all account for the top pulling up when it’s string up or any real pull on the neck from string tension. I don’t need to think about these things on a uke.

Right?


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Your last post shows you've worked it out, except for changes caused by string tension.

On my ukes I expect the sound board to pull up around 0.5mm, maybe a fraction more. I do build very light though.

So I tend to build for 2.5mm at the 12th if nothing moves, expecting to see a little more under tension. I make sure I have enough space to take the saddle down.

Awesome. Thanks, Chris!


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I build my ukes with a radius shaped soundboard with a 5mm thick fret board and bridge is 6mm tall. I built a ukulele size neck angle jig like the one Robbie uses for guitars. I adjust the jig so the neck angle will be machined to have about .5mm hight above the soundboard where the saddle will be located. Hope that makes sense.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
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Cairns, Australia

It does. So for my jig I would tilt the table so it’s 0.020 past zero in order to set the neck plane projected out to the saddle at .5mm.

I cut it at zero today, let’s see how this one goes and I will adjust from there.

Thanks for all the input!


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