What's the next size smaller than a Sopranissimo?

A luthier I follow on facebook is doing a "mini guitar" contest. The main requirement is that the overall length of the instrument must be 14" or less, and it must have string(s) that are "playable." I've never built something so tiny and feel like it's pretty clearly in the "novelty" category (at least for someone like me with normal sized hands) but it sounds like a fun and creative challenge, and I'm waiting on parts to get my table saw back in action so I can't really do anything serious right now anyways.

I'm planning on entering a uke. I did some googling and it looks like sopranissimo ukes typically have an 11" scale length and 17" overall length. Too big!

While eating lunch today I took out a clean sheet of paper and started drawing. I settled on a 10" scale length. If I use a 12th fret body join, that means I need 5" of neck proud of the body. If I allow 2.5" for a nice squat headstock (which is barely enough for tuners by the looks of it) that leaves 6.5" for the body, which seems slightly squatter than a typical sopranissimo. Those dimensions mean I can get from the 17" typical down to the 14" requirement. Not sure what this would be called though - a mini sopranissimo? Maybe I should just call it, "unplayable."

As mentioned I've never built anything near this tiny. Do any of you build in the sopranissimo size? I'm assuming the typical bracing is pretty minimal just because there's really not much width in a body this small. I'm wondering if there are other size related factors that aren't obvious?

I am going to build this from offcuts and scraps - looks like that means it'll be an all walnut body, maple or cherry neck and maple fretboard. I have a discarded bridge from a tenor uke that got a nasty chip on the corner, but if I cut it down to this size the chip will be cut away. Glad I saved it. I might have spruce scraps large enough for the top. Heck, this pattern is so small, I bet I could dig through my scrap bin and come up with enough bits to make a dozen of these. Should be fun. Wish me luck!



(I put a partially finished tenor fretboard in the photo to give a sense of size. That bridge, as is, is almost as wide as the body!)

I had half an hour between my day job and dinner, so I glued up the top plate and neck blank and went ahead and bent the sides. I had a single discarded side from another project for the sides on this versus two matched sides, so I bent it as one piece. I'm wondering if I'll even need a tail block?

The top is a bookmatched set of offcuts from a pair of sides I'm using on a tenor ukulele.

I was recently resawing some walnut for back and sides and I had one slice that curled significantly. I kept it anyways and I'll use it as a one piece back for this. I wanted the back on this to have some radius to it, so I'll just use the wood as-is with the radius already built in and sand the braces to match - it looks like it's maybe 4 or 5 feet radius.

Time to figure out bracing, to be continued....

Here is a tiny uke for you:

Interesting/nice video. A quick search on Youtube tells me this is a Brit called Ian Emmerson. On one of his videos he says the uke is made by Chris Reid aka Prof Chris-I assume that's the same Prof Chris who is a member of this forum?

Yes, that's me!

It was a challenging build, to say the least. I bent the sides over the barrel of a soldering iron, and luckily koa bends quite easily. From memory the top had one brace below the sound hole (about the size of a matchstick) and the back had no bracing but I sanded a curve (tail to heel) along the back profile, which was enough to give it strength.

Ian demanded friction tuners, so I had to invent some from brass tubing, interlocking inside the headstock.

I swore that I'd never build another, and so far I haven't been tempted.

The dimensions are half those of a normal soprano in all directions with one exception. If you make the neck width at the nut half size, it's almost unplayable even for Ian (and he can play anything!). So I made a mockup with the nut just 1/8 inch wider and sent it off to Ian, who agreed that it was just enough to make the difference. I think you can see that it doesn't appear to have different proportions from a normal soprano, which was the brief.

An alternative approach is the one taken by Andy Miles, also in the UK, who makes ukes with the same body size but a much wider nut. They can be played by a less exceptional player. You can find his builds on Facebook.

It's a Uke built on the atomic level. Think I would have to take a coarse rasp to my fingers!

Here is the smallest size uke I have built. It has a 9 1/4" playing scale, but I don't remember the overall length. Played fine, a bit trebley to say the least.
http://www.blackbearukuleles.net/detail.html?itemid=196

Wow Chris and BlackBearUkes! Those sound really tiny!

I got the fretboard cut and bound, glued a scrap of walnut in for a neck block, rough cut the neck blank...

I didn't want to just eyeball the task of sanding the sides to match the curved back, so I came up with a makeshift curved sanding form which happened to produce an exact match!

I'm trying to attach more photos but I can't seem to get the attachment feature working today...

Let's see if it works this time...

Your back curve sanding device is what I used, though I nailed down my battens rather than using weights and clamps - nails are so satisfyingly quick, a rare chance to use them in instrument building!

I thought about screwing it to a piece of scrap MDF but I didn't want to "ruin" my flat sanding plate (which is silly since it's just sheets of 80 grit glued to a scrap of hardboard). Now that I see how nice this curve turned out I may make a real radius dish with the same single axis curve, versus a typical dish.

I've been stalled because I am just not sure about bracing. I may go with a simple X brace with some smaller stock - maybe 1/8 x 3/16. That seems like the simplest. Or maybe a single brace across and two fan braces. This top is a little on the thin side so I'm nervous to just put a single brace below the soundhole with nothing at all down by the bridge.

dwizum said:

I thought about screwing it to a piece of scrap MDF but I didn't want to "ruin" my flat sanding plate (which is silly since it's just sheets of 80 grit glued to a scrap of hardboard). Now that I see how nice this curve turned out I may make a real radius dish with the same single axis curve, versus a typical dish.

I've been stalled because I am just not sure about bracing. I may go with a simple X brace with some smaller stock - maybe 1/8 x 3/16. That seems like the simplest. Or maybe a single brace across and two fan braces. This top is a little on the thin side so I'm nervous to just put a single brace below the soundhole with nothing at all down by the bridge.

Click to expand...

My test is to flex the top longitudinally, to see how it compares with other tops I've made. I suspect that even though your top is thin, it's still really stiff lengthwise. If so, minimal bracing! With such a small soundboard, there's a real danger of choking all the life out of it.

Thanks for the feedback - I glued it up last night, an X brace out of the thinnest piece of brace stock I felt able to handle and then scalloped it heavily. It taps about like I would expect and is still somewhat flexible. The top is barely .06" so I felt like it needed something just for durability's sake. I suppose the good news is, this is so simple and low-cost in terms of resources (free scraps!) that if I don't like it I can just build another. Such a small soundboard certainly doesn't need much though, it should get pretty stiff just from being glued to the sides I'm hoping.

I'd be interested to know anyone's thoughts on a neck joint this small as well. I'm already committed but there's always next time... For this one I'm just doing a plain old glued butt joint. I didn't want to deal with a bolted connection through such a tiny soundhole, and a tenon just seemed overkill...

dwizum said:

For this one I'm just doing a plain old glued butt joint. I didn't want to deal with a bolted connection through such a tiny soundhole, and a tenon just seemed overkill...

Click to expand...

Maybe a little butt joint with a little dowel or two. But be aware that that neck is more or less permanently attached. I know, I've tried to get doweled neck joints apart. Not fun.

I did a butt joint with a wood screw through the neck block into the heel. So I attached the neck before I put the back on.

The forces on the neck joint are tiny, because the short scale means very little leverage from string tension.

I drilled for two small dowels and just glued the back on this morning. No braces on the back as it's made pretty stiff from the curve. Next up is neck carve, and I'm thinking I'll put maple binding on the top to coordinate with the rosette.

It's put together and the first coats of sealer are drying. Will probably be playable by this weekend.



That's a half scale guitar neck drying next to it. Still can't get over how tiny this thing is!

dwizum said:

It's put together and the first coats of sealer are drying. Will probably be playable by this weekend.

View attachment 128593

That's a half scale guitar neck drying next to it. Still can't get over how tiny this thing is!

Click to expand...

I would suggest, you make the bridge about half the size you have it at now, it is too big and will restrict the sound on an already small top.

Thanks for the feedback. This is already smaller than my normal uke bridges, I was a little hesitant to make it TOO small but the more I stare at it, the more I think you're right and it's too big. It's hard to keep things in proportion to the smaller body, the body is small but I kept a wider string spacing versus scaling it accordingly. Maybe I'll try making a smaller one and if I'm comfortable with it I can use it instead of this one.

I did abandon the idea of using the cut-down bridge I had on hand and made this one from maple (instead of the ziricote that other one was made from) in the hopes of getting it lighter...

Half hour later and it's got a new and improved smaller thinner lighter bridge!