top brace inquiry

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Tudorp

Tudorp

Big guy with a lil' uke..
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I am in the home stretch of my Aphid build (the 10", 6.5" scale). I have the back on, and braced, but I am questioning if I should brace the top. Sure, I know how important bracing is, but this is a "Mini" uke, and I question how critical bracing is on such a small uke (Body is 4.5" long, by 3.5" wide at the lower bout). I braced the bottom, but not sure I want to brace the top to optimize the sound of such a small sound board. I have the lining for the top, but do you think on such a small body, not putting any cross bracing will help the sound, and not too much needed since it is a small soundboard? This Aphid is a novelty, but I want it to sound the best I can as small as it is.. I want it playable..

Thanks in advance..
 
Tudorp said:
I am in the home stretch of my Aphid build (the 10", 6.5" scale). I have the back on, and braced, but I am questioning if I should brace the top. Sure, I know how important bracing is, but this is a "Mini" uke, and I question how critical bracing is on such a small uke (Body is 4.5" long, by 3.5" wide at the lower bout). I braced the bottom, but not sure I want to brace the top to optimize the sound of such a small sound board. I have the lining for the top, but do you think on such a small body, not putting any cross bracing will help the sound, and not too much needed since it is a small soundboard? This Aphid is a novelty, but I want it to sound the best I can as small as it is.. I want it playable..

Thanks in advance..
Click to expand...

Hehe,...you want it playable,....TOO! :D

The soprano scale is "just" playable for me,....and i have medium sized hands. The tiny scale you're using is gonna
be tuff to play no matter what,.....unless you have tini-tiny-itti-bitti hands,......and i doubt that's the case!

I'd leave bracing off the top if it were me,.....as long as your top thickness isn't like balsa wood projects. I assume you will be stringing it lightly anyway,.....possibly with a Martin M600 set,.....or fishing line?

A lot of the old mahogany soprano ukes had no top bracing from what i read in a post on this site, (basis for another
alteration i made to one of my recent sopranos). It sounds sweet in tone now, and has opened up and sort of rings and
sings.

Mine i removed the fairly wide bridgeplate completely, and left just the 2 braces on either end of the soundhole, but thinned those to about 1/2 the original thickness. Strung with aquila nylguts, it's the uke i'm leaving out in reach for
a bit of fun whenever i want.
 
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For these I am using Jasper Happy's strings (from the UK), they are brighter, and thinner than standard strings, and closer in diameter with each other than standard. I found they work well on my Tangi mini. Yeah, playable is sort of asking allot I know, lol. Im not looking for something someone can "tour" with or a daily player. It is a novelty and fun, but the Tangi being a display piece, is sort of playable (for a laugh), but I am designing my mini to play better than the Tangi. Still gonna be pretty tiny sound I am sure, but, want to open it up the best it can be for it's size.. Thanks for the confirmation. I think I am going to leave the bracing out of the top.
 
If it's built light enough to sound good with the strings you're using, you're going to need a bit of bracing.

I'd be putting a transverse brace at the waist. It doesn't have to be large, but it's function is to help keep the top from sinking down around sound hole.
 
In my opinion, you should have a transverse brace below the sound hole and a thin bridge patch. A uke this small doesn't need any other braces. The bridge patch on a small uke is more for prevention against tops cracks than anything to do with sound, especially with mahogany. Removing the bridge patch on a soprano was not a smart move. You could have thinned the patch rather than do away with it altogether. As mahogany ages it gets brittle and cracks are more likely to occur. It will suffer the consequences.
 
I do have a bridge pad, but just large enough to fully hold the bridge. I did not put a transfers brace under the soundhole tho. I think I can retrofit one in there after the fact, so I will hold that thought for now. I didn't think about sagging around the hole, so I want to monitor that pretty close. I am hoping it is small enough that it won't have that problem. The top and bottom both are 2mm thick, I didn't want to go any thinner, but thought that might be thin enough to let the soundboard ring.
 
2mm is thick? (am I getting my metric messed up again? It's about 1/16th"?
But that is also before final sanding so a smidge will still come off..

BTW: now that it's together, I have been tapping the sound board, and humming a tone in the sound hole. It does seem to resonate pretty cool.. Hmm.. Not sure if that is a scientific sound test or not.. lol
 
I make mahogany soprano tops 1.5 mm. And the cherry tops on my piccolos are 1.5 but thinner around the edges. Build a few, with different thicknesses and different bracing patterns. It's the only way to find out what works, you know.
 
Yup.. true.. Gonna.. But this is my 1st real scratch build and I was kinda intimidated to go any thinner.. But, after final sanding, it will end up 1.5 or so anyway.. If it sounds muddier than I am looking for out of it, I might do the next one thinner yet..

thanks..
 
It would seem to me that you don't have very good knowledge of what forces are at play in a uke, that is, where the instrument is trying to pull itself apart, where it's trying to implode, where there's not much force acting at all and where leverage is multiplying the acting forces. If you did you'd understand where the instrument needs very stiff support and where the instrument can be very much lightened up. You also don't seem to understand how stiffness acts in relation to width, thickness and length. You also seem to be working on 32mm=1".

Overall you're building your aphid heavier than I build my tenors.
 
I just have to say...and this relates to another thread on this forum...if you spend more time writing and talking about uke (or guitar, or whateverthefu..) building than you do in the actual act of making the things, you're missing the real truth.

There is nothing...NOTHING...like building a whole crapload of instruments, getting them out there, and paying attention to how your instruments are used as MUSICAL TOOLS!

Are we making wall hanging art? Or are we making musical instruments? Precious is as precious does. I see a few...a very few...builders who are so beyond the musical thing...they've got that down pat...that they can go deep into inlay (Chuck Moore, I'm talkin' 'bout you!) and it only enhances the fundamentals of what they build. There are certainly others, and I'll give a major thumbs up to one of my own staff luthers, Jake MacClay of Hive Ukes. But the point is that what we're making are the tools of another artist's trade.

Get over the rush of simply being able to bend sides or make a ULO (Ukulele-Like-Object), and get down to the task of making a real musical instrument.

It's all about the MUSIC, isn't it? Or is it just a wank, an ego game for us brilliant craftsmen of the New Golden Age of lutherie?
 
Well said Rick, I'd like to add that most of it applies to a hobbyist's practice as well.

And Tudorp, don't rush things. When you asked your question about bracing, you got ONE answer from a non-builder, pointing you to ONE thread of six or seven posts, the bottom line of said thread was that SOME ukes weren't braced.

I mean, why even bother asking in this forum?
 
I think it's a great idea for anyyone interested in building instruments to study how others are put together. Those interments that last have design features that work and are there for a reason. Have a think about what each of those components do in the design and what forces that they are trying to control. Whether it be tension or compression.

Also, if you don't know what the cube rule is about, then you have some more studying to do.
 
Roger Siminoff makes a clear distinction between "braces" and "tone bars", and while all braces affect tone, you can identify which do more of one job than the other.

In my acoustic guitars and a few of my more experimental ukes I use carbon fiber "flying buttresses" from the waist area of the sides up to the neck block to completely free the upper bout top from the structural responsibility of supporting the compressive forces of the neck and fingerboard. I consider the "X" brace to have both structural as well as tone shaping effects, but below the "X" the braces are more primarily tone bars which affect the flexibility of the top and help to establish nodes and anti-nodes of vibration. This has a major effect on the midrange response of an acoustic guitar. Rather than the usual diagonals, I often go with a three fan tone bar system there which gives the guitars a bit more midrange push. It's like a bit of Sel-Mac or archtop spice added to the flattop sound.
 
That is pretty interesting, and I had no idea that the braces are also designed to effect a specific tone. I knew that they effect it, just by dampening the soundboard, but man, it basically what you are saying, it's an actual science too in the perspective on design and tone. The more I do learn about what makes an acoustic tick, the more fasinating it actually is. I had no idea.
 
The entire topic of vibrational nodes and the effects of tone bars on them is fascinating. Here are photos of a guitar top recently built for me by a luthier with a PhD in chemistry who evaluates the nodes on his tops at various frequencies before determining bracing. The lines on the soundboards are mustard seeds that have formed patterns in response to the vibrations. This stuff is way over my head but very cool to observe.

P1040355.jpgP1040354.jpgP1040356.jpg
 
mzuch said:
The entire topic of vibrational nodes and the effects of tone bars on them is fascinating. Here are photos of a guitar top recently built for me by a luthier with a PhD in chemistry who evaluates the nodes on his tops at various frequencies before determining bracing. The lines on the soundboards are mustard seeds that have formed patterns in response to the vibrations. This stuff is way over my head but very cool to observe.

View attachment 27452View attachment 27451View attachment 27453
Click to expand...

That is just too cool. At 50 years old, and being a "muscician" for 30+ of those, but only within the last year digging into the mechanics of building ukes, I am WAY too old to start trying to master all of that, but I will promise you I will try to learn about all that I can. Frankly, I don't have enough time left on this planet to learn all that stuff, it is way deep, and way cool brother.. I had my career path, and it was electrical engineering and control. But I tell ya, sometimes I wish I took this part of it more seriosly 30+ years ago too.. Good stuff..
 
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