Official Luthiers Forum!

Hello,

I'm hoping someone can help me with a uke neck angle problem. I'm building a Tenor uke, 12-fret to the body. The fretboard got a little thin on me, closer to 3.5mm than the called for 4.5 in the plan.

Searching here I found the 1/8" drill bit test. Below are some pics. It looks like the 1/8th" bit at the 14th and straightedge on the first comes just to the top of the bridge. In the previous forum post it was recommended that it land at the top of the saddle.

What would be the recommended approach? Lower the bridge by 1.5mm or so in order to allow the saddle to stick up 1.5mm? Should I try to adjust the neck angle? It was put on flat, but I think the fretboard getting too thin caused the issue.

Other ways to work around it?

Here are some pics:







Thanks!
Brad

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

I would move the bit back to the 12 fret. I suspect the test was for a 14 fret to the body ukulele. That would simulate about 2.5 mm of action at the 12th fret.

_________________
http://www.Harvestmoonguitars.com

Thanks, John.

With the bit at the 12th it's pretty much the same. I'm right at the top of the bridge which is around 8mm thick. Should I maybe shave the needed amount from the bridge or consider alternate options? I have the fretboard extension tacked down but could get it back up pretty easily if I need to change the neck angle.


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

You need to end up achieving three things:

1. Your desired 12th fret string height, say 2.5 mm.

2. Enough saddle so the string can break over it, with a margin to allow you to take the saddle height down if the top pulls up under string tension. I'd say 2 -3 mm.

3. Strings far enough above the top to make playing comfortable and give you sufficient volume. Anything less than 6mm is, I think, problematic.

So, if your drill bit gives you 2.5mm at the 12th, if that's what you want, then you could go either way.

Reduce bridge height to 6 mm, allowing you 2 mm saddle. But you're right down at what I'd consider the lower margin.

Reset neck to keep your 8mm bridge and give you 3mm saddle, which will probably need to be reduced to 2mm under tension. Or whatever numbers you like, though 1.5 mm is low for my taste (but I build light so expect the top to belly up).

The first is easiest, and would probably turn out fine.

The second gives you a margin for the long term and might give you a touch more volume.

Cool. Thanks! I'll shave the bridge down and then deepen the saddle slot to accommodate the new height. Let's see how it goes from there. I appreciate the insight and the options. It helps me better understand the whole setup.

Thanks!
Brad


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

If it were me, I would change the neck angle to give myself more options later.

Is that bocote? Wow nice!

_________________
Pat

Thanks, Pat. It is indeed Bocote. The fretboard, bridge, B&S and front and back headstock plates.

Question for you - I already have the threaded insert installed so will have to take that back out to adjust the neck. Would the hole wind up off center if I drop the neck back? It seems like it would but I could open the hole in the block up a bit to accommodate? Or maybe it won't matter at all.


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

you can open the hole in the block if you need to.

_________________
http://www.Harvestmoonguitars.com

what kind of joint? you shouldn't need to take out the inserts, provided you sunk them in a little deeper than the surface. Even so, you can file them down a little. We are not talking about that much. And yes you can enlarge the holes in the head block a little. The angle shouldn't be too off.

_________________
Pat

That's a sweet looking uke. The bocote looks great. I hope you post photos when it's done.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

It's a single bolt butt joint. I did recess the insert but only maybe a mm at most. Your right though it won't take much. I'll give it a shot this weekend. Thanks for the help!


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Thanks. I will post pics for sure. This is my first scratch Uke. I did build one of the SM kits before. This is for my sons guitar teacher. I hope it doesn't sound awful.


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

For a butt joint, you don't want to use the file. I used a little Dremel grinding wheel on the insert before I adjusted the angle.

_________________
Pat

IMO, the solution to your fix depends on what you're going to do with the instrument.

I'd change the fretboard. Anything you do from here is a concession.

Caveat - there's always a fix, or concession. If you take down the bridge, this will result in an obvious one, IF you know the specs/plan.

One thing I wouldn't do is change the neck angle, unless you're going to shim under the fretboard so it stays flat. You're thinking of introducing a negative angle, which means there will be "roll off" on the higher frets, and higher action up top if you don't shim up the fretboard extension over the body.
Note: whether you know the plans or not, this will be noticed.

Since you're "giving it away" I presume, I'd adjust the bridge. If it's going to a guitar player, you probably want playability up the fretboard.

Thanks, Aaron. I ended up splitting the difference basically. I dropped the neck back a bit and shaved the bridge down to 7mm.

Here is the results so far:



I'm going to string it up and shape the nut tomorrow.


Sent from my iPhone using Tapatalk

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars