View Full Version : I messed up my neck

06-14-2010, 10:18 PM
First let me say this all completely new to me. I thought it would be a great idea to build a soprano ukulele for a good friend of mine. I've never built an instrument and i've never actually touched a ukulele. I don't even remember how I got the idea. The hardest thing was bending the sides. I had pretty good luck using a homemade bending iron (curling iron half wrapped in copper wire)

I've been using the free plans from grellier.fr.....but with a spanish neck (made more sense?). The neck and body are all put together. I started trying to figure out the frets when i noticed i made my neck about an inch too long...12 frets the plans call for do not reach the body.

what i really want to know is do i have to stick with the 13.75" scale the plans call for, or can i use a 15" scale to compensate for my long neck? I was using the stewmac fret calculator and this seemed like a solution? I really do not know much about this.

bit off more than i could chew :D

06-14-2010, 11:04 PM
Sounds like you're on the right track with the stewmac fret calculator. I guess you have several different options, but you can't really get around the fact that the modified neck defines a new scale length and that's the length you have to use for calculating the fret positions. So you have a soprano with a 14.75" scale - cool, you just added tension to the strings and made the instrument louder. If what you wanted was a totally soft, quiet, mellow soprano sound, then yes you messed up, but otherwise I wouldn't worry about it.

What you have to accept, if you go this route, is that the fret-to-body match is not exact - that's the only real "flaw" you'll have. If my quick calculation is correct, you would end up with the neck joining the body right in between the 12th and 13th frets (you'll have to add the 13th, as the plans only call for 12 frets). If that really bothers you, then you would have to think about other options like adjusting the bridge/saddle or nut position just enough to get a better fret-to-body match (at the 12th or 13th but not smack in between).

Let us know how things turn out.

06-14-2010, 11:06 PM
I'm having a little bit of difficulty trying to visualise what your are saying.

Is it that the neck is too long for a 12th fret body join? Will it work if it joins at the 14th instead? Both common configurations by the way.

If you vary the scale length to a 15" concert one, then were is that going to put the bridge on your body shape? Might work, and might not. The same goes with using the Soprano scale length and changing where the neck joins the body. ie 12 or 14 fret. You need to plan out your bracing for where the bridge is going to land.

06-15-2010, 12:49 AM
Allan, I think artanis said the neck and body are "all put together" - so adjustments to the bracing, bridge position, etc. may or may not be possible at all. With the small soprano body they would not really be recommended (unless very minimal like a few mm). That rules out just joining at the 14th with the same scale length, as it would move the bridge/saddle almost 20 mm closer to the soundhole.

06-15-2010, 01:13 AM
Well, that's a real dilemma isn't it?

The only solution that I can see is to either scrap this one....not really an ideal solution for a first go. Kind of demoralising. Or to live with a solution that Erich offered, as the bridge position is pretty well set, give or take a few millimetres.

06-15-2010, 05:04 AM
Correction to what I wrote before. As I see it (assuming you have added 1 inch to the neck) your neck/body joint is a wee bit beyond the 13th fret if you add the inch to your scale length.

Here's my math (in millimeters, cos that's what I use)

Original plan
Scale length: 349
12th fret: 174.5 (from the nut)
Neck/body joint: 174.5 (from the nut)

Modified plan
Scale length: 375 (0.6 mm longer than the extra inch, but the calculator doesn't like fractioned millimeters)
Nut to 12th fret: 187.5
Nut to 13th fret: 198
Nut to neck/body joint: 200
Nut to 14th fret: 208

Sorry, if you want a really close, almost perfect fit you'll have to go up to 378 mm scale length, which you might be able to do by moving the nut and the saddle 1.5 mm each. Of couse everything in between 375 and 378 gets you a little closer, but also requires some adjustment to the nut (and or saddle) position, whereas the 375 should work without further stress, and with the rounded soprano body it probably won't be very noticable, if at all.

06-15-2010, 09:15 AM
I'd go with the 375mm scale length and 13th fret joint. The bridge will only be 2.5mm lower on the body (plus compensation from the fret calculator). Sounds like the best solution....just don't forget to buy concert length strings

06-15-2010, 10:16 AM
Necks don't have to join at a fret..just place the bridge in the correct place over the bridge patch (important bit)... then measure from the bridge to the nut... and whatever that is, is the scale of the uke.
Then just work out the math,s for the frets based on that...Oh and don't forget to knock off a couple of mm's to compensatethe bridge...or do it like Erich says..it'll be ok.

06-15-2010, 02:14 PM
wow that was all very helpful and really fast. Thank you all for the advice. Its all coming along nicely.

06-15-2010, 10:46 PM
Necks don't have to join at a fret..

Ken, good point with the compensation - something like 2 mm is probably called for. And, of course, you're certainly right about joining at a fret - from an acoustic and structural point of view.

On the other hand, if you look around at guitars, ukes, mandolins... I don't know how many I've played but there were only about four that didn't join at a fret. BTW, one of them is my custom Brüko uke which I almost sent back when I saw it, but the sound was so amazing I decided I could live with the neck joint smack between 12 and 13. So yes, necks don't need to join at a fret. But, in the same vein, nor do we need rosettes, headstock veneers, fret markers, inlays of any kind... even binding is debatable if you do a good job of sealing and finishing the edges.

Artanis, you may want to use a fret marker on the 12th fret so that it can be easily found. Most ukes join at the 12th or sometimes at the 14th fret, so that's what players expect. If it joins at the 12th you can play a uke blind without fret markers, because...