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I started my first uke some time ago and it has set for far too long. I'm starting work again and I have some questions I was hoping I might find some answers to. I don't have a lot of experience playing the uke, so please forgive my ignorance. I'm building a soprano from the Grellier plans, which is a copy of a vintage Martin, I believe. I have the top and back joined and thicknessed. I will be thinning and bending the sides shortly. Most of the info is there in the plans, but I was wondering about some of the finer points.

The plan calls for a scale length of 13.74". I was thinking of using either my 24.9 or 25.4 fret template and starting at fret 10 or 11 (depending) and getting a scale length of either 13.455 or 13.975. First of all, does that line of reasoning make sense? Second, would you rather go slightly shorter or longer than the 13.74 scale length and why?

I have no idea what kind of setup/action numbers to shoot for on a uke. How much relief? Compensation? What kind of action at the nut? 12th fret? How high above the sound board should the strings be (bridge + saddle height)?

I intend to build this uke light. The top, back and sides will likely end up around 0.060". I'm really hoping to obtain a very ukey sound. If there is any othe advice you have for me, I'd love to hear it. I'm sure there are more questions I will have, as well.

Thanks in advance for all of your help.

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sweat the small stuff.

If you can locate and download a program called wfret, you can choose any scale length you desire and print out a template.

I'd go for the slightly shorter scale length. Mainly because I prefer that (I tend to build my ukes with a 13 inch scale), but also because the "usual" range for sopranos is from 13 inches (the early Hawaiian builders such as Kumalae) to 13.74 inches (Martin). Also, the longer scale might not fit a soprano uke case, if that's of relevance.

But if this uke is for you to play, capo a guitar at the right places and then build what feels most comfortable.

0.60 is a bit light for the top in my view. Ken Timms builds excellent replicas of the 20s Martins, based on measuring several, and ends up at pretty much 1.8 mm (.070 inches). For my ukes I initially thickness to 2mm (.080) and work down from there until the soundboard feels about right, which is usually around .070.

The risk with going too light is that the uke can sound twangy, like a banjo, though you can compensate to some extent with bracing I guess.

This assumes you are using mahogany or another hardwood. A softwood top wants be more like .080 or it will sound very harsh and trebly in my experience. And I find that spruce is not good for a figure 8 soprano because it is particularly strong in the higher frequencies, plus the sustain tends to muddy the sound if you strum (oddly, spruce works for a cigar box shape which is a bigger soundboard area, or a round camp uke which has a smaller soundboard area!). Cedar is OK, though the sustain is still an issue. English yew is excellent, if you can find it, and I'd guess Pacific yew would be good too.

The Grellier bracing is thought to be rather heavy, so bear that in mind.

Action at the 12th fret is usually between 3mm (0.120) and 2mm (.080). Lower will buzz when strummed unless you play very gently and, as a good player once said to me, the soprano uke is as much a percussion instrument as anything, so I'd want to allow room for some vigorous playing. 2.5mm (.100) suits my own playing style and that of some professional musicians I know. If this is for you, and you haven't played uke before, I'd suggest you start at 2.7mm to 3mm but build in scope to lower the action to 2.5mm once your playing becomes more precise - the higher action gives some margin for unintentional heavy-handedness.

Relief - none!

Action at nut - as low as possible, i.e. a string fretted between 2 and 3 should just *barely* clear fret 1. Low tension strings mean that you can sharpen a string noticeably just by fretting a bit harder, and if the action is high at the nut then any barred chords on the lower frets sound horribly out of tune (Bb, 3211, is notoriously difficult for new players with cheap ukes because the action there is always far too high).

And I should add that it's worth compensating the saddle. The thick C string requires a surprising amount of compensation, probably around 2.5mm if you use Aguila Nylgut strings or nylon, a bit less if you use fluorocarbon strings. Without compensation the C will play noticeably sharp from the 5th fret upwards, though those whose playing is simply strumming to accompany singing tend rarely to reach such dizzy heights! I like the option of ending a song in F or G with a higher inversion (5558 for F, 77710 for G) and prefer that to be as in tune as a uke ever can be.

I just built my first too, a soprano. I went down to .7in on a mahogany top and did a deflection test on it for future use. I'm thinking I will go a bit thicker next time, or less deflection anyway. Wood is variable yadda yadda so there's that caveat. I had all the same questions before I built my first and still do

But I based mine off of an existing Uke and what I found was that the neck/body relationship is similar to a classical guitar, there is no back angle to the neck and in fact could probably almost be a forward angle. THe neck on my Uke was set straight in line with the body so after the fretbaord and frets and action at the 12th fret the string height at the bridge is 7/16th inch.

Wayne, thanks for the info. I think for this one I will stick with the templates I have. That is assuming what I was planning on doing will work. I think it will...

Chris, I really appreciate your detailed response! I've already got the top and back thicknessed, so if the finished product implodes or sounds like a banjo, I'll have to apply my knowledge to the next one. I'm building with curly mango, by the way. So I guess in the same family of wood densities as koa, hog, etc.

I'm surprised to hear you say that the Grellier plans are overbraced. Not because I have any experience to say otherwise, but my first thought was, "Whoa! There's not a lot of wood there!" Plans call for 1.5mm thickness on top, back and sides. There are two back and two top braces, all 6mm x 6mm, and a bridge patch 2mm thick. Other than the carving of the braces, is there someplace you would go lighter with the bracing?

The purfling scheme I have in mind is relatively wide, around 0.125". Do you have any recommendations for lining width? I was thinking of doubling up two thinner pieces of side off cuts or possibly some old spruce soundboard scraps. Any experience there?

How about nut/saddle material? Plan calls for ebony. I have both ebony and bone. Maybe the ebony would help control some of the twang if I did go too thin?

I've built a couple of acoustic guitars, but anything uke related is completely new to me. So thanks for your patience.

Oh, one more! Tie block vs. the slotted, but pinless bridge (sorry, I don't know what to call it). Plans have the latter type of bridge drawn. It seems really simple, but I wasn't sure if it has any downfalls compared to a tie block style bridge.

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sweat the small stuff.

Hi Heath, I think I'll chime in here because I build a number of ukuleles these days, though I agree with a lot of what has been said so far. You might want to take some of this FWIW since I usually make tenors.

I use my other templates for slotting and your shorter scale is one I use for sopranos.

As for thickness it depends on the intended music to be played. If you want it as a percussive Hawaiian style instrument for large group play then .070 with a hardwood top is fine. If you want it more as a melodic fingerstyle instrument with fewer people playing then .060 works better for me.

I tend to like thinner tops with taller, thinner braces, 3/16+ X 5/16 and I don't shy away from the right kind of spruce.

My action is usually about .080 and the compensation to the front of the saddle is +2mm with an 1/8" saddle.

I don't care much for the slotted bridges as the slots can widen over time. String through bridges are alright as are tie block bridges. I usually make 12 hole tie blocks for a cleaner look and less chance of marking the top if a string slips.

Your string height at the saddle can depend on how thick you want your fretboard to be. My fretboards are usually about 1/4 inch and are often ebony with the string height at the saddle about 7/16.

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Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

I'd go along with Ken's points. The final bracing really depends on how flexible the top turns out to be - I want to be able to flex it longitudinally with just light finger pressure but it should still feel stiff. Two consecutive slices from the same board can behave quite differently when thicknessed!

I'd start with braces like Ken's - narrower but taller than the Grellier plans. My bracing is nearer 1/8 wide than 1/4. Height is the most important factor for stiffness, width adds weight (which you don't generally want) more than it adds stiffness. Then flex the top and take down the height until it feels like it wants to make music. I taper my braces to nothing before they meet the sides, but most builders taper them quite a lot but leave enough to tuck into the linings. Tucking them makes the top stiffer, but also makes the braces less likely to come unglued if the top takes a knock.

Solid linings made from side offcuts add more stiffness to the body than does kerfed lining. One strip is enough glueing surface to hold the top on, but you obviously need to add enough to allow for your binding and purflings. I focus on keeping the weight down as far as possible so if I need to double up linings I'll make the inner piece shorter than the outer (so long as I don't cut it all away when binding!).

I also curve the back aggressively fore and aft, with a small curve sided to side by shaping the back brace(s). This helps keep the light body rigid, and I also think produces more volume.

I use simple slotted bridges (again to keep weight down), as small as possible. The slots do risk wear over time, but I've not found any reasonably hard wood (e.g. rosewood) to be a problem so far - no visible wear over 8 years, since I started building.

Ken, thanks for chiming in. Maybe I'm just reading what I want to hear, but I feel like everything you said feels right.

I think melodic fingerstyle would describe at least how I would like to play/hear a ukulele, so hopefully I'm on to something there.

I'm glad to hear someone else has tried using the guitar scale length templates for a soprano.

I've never really thought about how fretboard thickness can effect string height above the soundboard before. That was sort of an "aha" moment for me. Thanks for pointing that out. My plans call for a 3mm thick fretboard. I'll have to give that some extra thought.



Chris, close to 1/8" braces is crazy! I will definitely go with something narrower than 1/4". Thanks for that advice.


Really, thank you Ken and Chris so much for all of your advice.

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sweat the small stuff.

hI HEATH MY PLANS call for 4.5mm FB and I use between 4.5 -5mm depending on species of wood used. You can vary the height of the bridge to match your FB and string height at the 12 th fret to match your intended action .

And I'd say, don't make your bridge until you've built the uke and got the fretboard on. These days mine turn out roughly the shape I intended, but the early ones had rather more variation

The easy way to work out your bridge height, once the frets are on, is to place a drill bit of the required size at the 12th fret (e.g., if I want 2.5mm action at the 12th fret then I put a 3mm drill bit next to the 12th fret - its top will be pretty much 2.5 mm above the top of the fret).

Then rest a straight edge on the 1st fret (or even better, the zero fret if you use one). Mark where the front of the saddle is to go on the body (on tape, not the wood) and measure up from there to the straight edge.

That is roughly where the peak of your saddle will be. Let's say you measure 12mm. Then decide how much saddle you want sticking up, to allow for adjustment (2mm probably). That tells you your bridge should be 10mm tall.

Now you can make the bridge.

Of course, it won't turn out exactly like that. String tension might arc the neck a tiny amount, and will probably pull up the top a fraction. If I thought that would happen I'd allow a fraction extra saddle, say 3mm total, and make the bridge 9mm thick. Then, if the top pulls up 1mm, I'll need to take 1mm off the saddle.

You can't get the saddle height exactly right until the strings have been on for a day or two.

I've been following David Hurd's recommendations on uke bracing and thickness. Basically, they're small Classical guitars, and all you really need to do is scale the thickness and bracing to suit. So far I've just been making tenors, and scale the thickness to about 70% of what I'd use on a Classical guitar. The most successful one to date had a Sitka top with a high Young's modulus (18,000 megaPascals along the grain) that was 1.5mm (~.06") thick. For a more normal piece of Euro I might up that by .01", or a bit more if it was particularly low in density. I used five fans that were (iirc) about 4mm wide and 3 mm tall, and two cutoffs, along with the usual parallel bars at the waist and upper bout. I'm pretty sure I used a doubler on the sound hole with 'A' braces on either side. The B&S were Osage Orange. The buyer said it was the loudest and best sounding uke he'd ever heard. IMO most ukes are over braced.

Alan, I'd disagree. The small classical guitar approach is fine for tenors, but a soprano is quite a different beast. I've not yet encountered a soprano built that way which really works.Thats not to say you couldn't manage it, but I haven't yet encountered one built that way which was good.

And there are alternative ways to build tenors (try a Kamaka or Koaloha tenor if you can find one, the former being the traditional Hawaiian approach and the latter the modern Hawaiian - neither is built or sounds like a small classical).

I'm increasingly coming to the opinion that, for a soprano, there is a close correlation between mass and volume/sound quality. My best so far is 240g with wooden pegs, and it's loudness always amazes listeners. Beaten by my 20s Kumalae, also wooden pegs, at 220g (but with iffy intonation and an agricultural neck profile - guess you can't have everything).

Sound quality shouldn't go with volume, but all the quiet sopranos I've played sound muffled too. Loud can be harsh sounding, but usually isn't.

Mind you, I'm a mere hobby builder with only around 40 sopranos (and a handful of other instruments) under my belt. But the last 30 or so have been admired by uke players, including some professional musicians, so I'm doing something right.

In case it helps anyone, this is what I aim for in a soprano:

1. 300g or less in total weight, including tuners and strings.

2. Maximum 2 ladder braces, no bigger than W4mm X H 7mm, smaller if possible, tapered to nothing at the ends. One brace on some body shapes.

3. A tiny bridge patch, maybe even no bridge patch.

4. Bridge as small and light as will stay glued on.

5. I should be wincing as I put the strings on for the first time for fear it will collapse!

Thank you guys for contributing so much to this thread!

For those of you who use a bolt-on butt-joint neck, what size threaded inserts do you use and approximately where do you locate the insert in the neck? I'm eye-balling it right now and trying to make the best compromise between centered from fret board side to heel cap side and enough depth that I don't shoot through the other side of the heel with the insert. Any suggestions? My plan calls for a dovetail joint.

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sweat the small stuff.

This should be inspiration enough for me to build one too. Just haven't got around to it.

http://ez2url.com/good-bad-ugly.html

My inserts take 5mm hex socket bolts, but 6mm (1/4 inch) would be fine. 1/8 inch bolts would probably be strong enough to be honest, there isn't much stress on the joint.

I like the inserts to be at least 1/3 of the way down from the fretboard surface of the neck but suspect 1/4 the way down would be enough. If you imagine the heel/body joint as a seesaw (teeter-totter in American?) with the bolt as its pivot, then it's the surface above the pivot which resists the neck pulling up, by pressing against the body (strengthened by the head block). You just need enough of this to resist rotation.

I use 2 thin inserts 1/8 in for tenors, and steel threaded inserts into the neck to accomodate the black allen headed machine screws. I space mine as follows. e.g. 75mm heel block 1st one is 25mm from the top second is 25mm from bottom . These are for our tenors only.. Lock the machine screws down equally when aligning neck to body watch for center alignment. recheck alignment of FB to bridge after fully tightening the screws. Make sure there is no unwanted rotation/play or tilting of the neck to body joint

Thanks for the advice, guys. I think I will heed the call to use a slightly smaller hex bolt and insert. Perhaps not 1/8", but the 5mm sounds like a good compromise. I'll shoot for a bolt somewhere between 1/3 and 1/2 of the way down, depending on my heel profile. I'm not that brave, but I've read of people just using a glued butt joint on sopranos, so I'm guessing it doesn't take much to hold the neck on in the first place.

This has been fun project so far! I'll share some photos with you guys shortly. Thanks, again!

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sweat the small stuff.

1/4"x20. Brass threaded insert into a M&T neck joint, for tenors. I use 2, but 1 placed as close to the bottom of the heel as you can stand would be where I'd put it.
Caveat - If you're gluing the neck, I'd put it in the middle to pull the joint tight.

Here's a short clip of how I install the inserts the correct way.

Hi aaron , I have the dowelling jig/inserts , what do you call that t handled wrench from woodcraft ? and what was the original size? I assume you ground it to fit the brass insert/dowel jig ?? thanks ernie

Threaded insert wrench.

Same size as the insert - 1/4x20, I think that's how they size it.

I lightly ground the paint off the shaft just so it fit in the doweling jig. Took me years to figure this one out. . .

thanks aaron I use a steel threaded insert which takes an allen key and allen headed machine screw done through the soundhole , and into the heelblock, but for sopranos I might try and use the brass inserts. I/ve had a problem with th brass inserts breaking in the past , but with that video and the insert tool/dowel jig it looks a lot easier!

I.don't care for the Allen inserts- they strip easily.

I've had the brass ones break in the past as well, when I used a screwdriver and installed them the wrong way. Funny, I just saw a few Youtube vids that show the installation of the brass inserts the wrong way, slot side out. Some of the comments we're "you're doing it wrong". You think they'd pull the vid, but they still exist.

Your right aaron i used the brass and screwdriver routine an screwed it up on my own without watching a video. About 8 yrs ago. I have not had a problem with allen headed steel inserts. For softer necks I use a oak dowel through the neck , so the steel threaded inserts have something hard to bite into .I use a swivel headed allen key to lock the allen headed machine screw through the s, hole. I found that I do have the insert tool you mentioned I used it for reinstalling stripped out threads about 25 yrs ago ,DUH!! after seeing your video . I will try the brass inserts on my softer necks e.g. soprano and concert. Thanks again for your input!! aloha

I really like the Allen key ones and have not yet had any problems with them. On the two soprano ukes I have built very recently, I used just one insert located just under the half way point of the heal towards the heal cap. I like the furniture bolts which are easy to get at Lowes.