Khaya & Sitka Spruce Pineapple #005

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saltytri

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This is the point in the building process where it feels like it really will turn into a ukulele. The box is nearly ready to be closed after the back braces are shaped. The neck is roughed out, trial fit and adjusted to confirm that it is straight longitudinally and tilted to get the string height right. The fretboard and peg head plate are ready to glue into place.

The materials, in addition to the Khaya back and sides and the Sitka spruce top, are Engelmann spruce braces and tone bars, Indian Rosewood fretboard and bridge and neck of Honduras mahogany with Port Orford cedar for the stringer. The neck will also get two carbon tubes that are .21" in diameter.

I finally got around to setting up a rig to cut binding channels. This one will get Granadillo bindings to protect the edges of the Sitka top and to match a back strip of the same wood. More on that later....
 
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Nice clean looking work. I find it curious you are using Engelmann for the braces. I find it too soft for that job, but maybe you have a plan. I am a firm believer that the BEST spruce in any plucked string instrument should be the bracing material. I have found, doing several stress tests over the years, that Sitka is the best choice for me. If the braces relax or fail down the road, the whole instrument suffers.

Also, I don't know how much you are going to gain by installing two carbon fiber rods. I would think one more than sufficient for a uke. Thoughts? Thanks for sharing.
 
Thanks for the comments - this is most of the reason for posting the builds here. So much of this art/craft falls into the realm of lore and it is very helpful to hear from the voice of experience.

If Sitka is generally the better choice, I'm glad to know it and that's what I'll use in preference to Engelmann. In this instance, I had some of the latter that was sold for bracing by a well-regarded supplier, so I used it. That's not a particularly good reason for making that choice but I guess the learning curve isn't smooth.

As for the carbon tubes, I happen to have a quantity of .21" arrow shafts left over from another project. They are smaller and, therefore, slightly less stiff than the .25" round tubes and square rods that others seem to use quite a bit. Once the setup is done to rout a groove for one tube, a second groove takes no time at all. I do this on a mill so aligning for the second groove takes no more than cranking the table on one axis. So, it seemed reasonable to use two tubes.

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Same for gluing them into place - not much additional work or epoxy. At any rate, I'm pretty sure that the peg head is never going to snap off!
 
You're right, you are safe with that peg head. It seems to me that if you are installing tubes instead of rod, you may have been better off not installing any kind of reinforcement. Don't know, just thinking out loud. I'm probably thinking of fishing poles. How stiff are those arrow shafts?
BTWm great looking build. My work is clean when it's finished but nowhere near that clean during the process!
 
Moore Bettah Ukuleles said:
My work is clean when it's finished but nowhere near that clean during the process!
Click to expand...

That's one of the many differences between pros and amateurs. You guys know where and when to put your attention! I poke along trying to make everything right at every step, which sometimes wastes effort. Live and learn. And yours does come out a little better in the end. ;)

These tubes are very stiff. The wall is .044" which is pretty thick, not like the light tubes that get used in kites, for example. Though I'm not an engineer, I think it's true that even in a solid rod, it's the outer part of the rod that does most of the work in resisting flex. The closer a fiber is to the axis of flexion, the less work it does. So, a tube makes sense in that it gives most of the stiffness of a solid rod of the same diameter while eliminating some weight.

BTW, I saw Woody (of Moorea) featured on your web site. I ran across him a couple of weeks ago. Nice guy, and he was even nice enough to sell me some of his kou from Apataki. There's a pretty uke lurking in that wood.
 
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I am certainly an amateur but from one amateur to another, your uke looks amazing!!!!!. I also tend to use what i have. I do have a number of graphite shafts (I make custom fit golf clubs) and I was considering using the shafts for reinforcement. The only issue I see is golf club shafts are tapered unlike arrow shafts. Not even sure how to cut a channel for that....:confused: Great work and will watch with interest on how you complete this uke and hopefully, you will give us a sound clip.

Tom
 
Neck reinforcement? Never understood it on a ukulele tho I did try it once. I've yet to read any qualified justification for this particular bit of overkill tho I suspect I will now get it :)

As for the rest - nice clean work.
 
Thanks, Pete. As for the neck, who needs any more justification than that Chuck does it? :D:D

Not too sure about BaldEagle's tapered shafts, though. I'm going to stop thinking about it so I don't spend all day figuring out how to do it.
 
Pete Howlett said:
Yeah - I guess in his long life he has lead many astray :) :)
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What builder of instruments has NOT seem his share of ukulele necks that are twisted or bowed? I certainly have. By installing the correct stiffener in the neck I can be pretty assured that when it leaves the shop that necks isn't going to move a whole lot. I've done them both ways, I know it makes a difference. No more wondering about how much the string tension is going to affect the trueness of the neck over the instrument's lifetime. Once my relief is set, I know it's going to stay that way. For me, installing a CF rod takes almost no time and cost mere pennies. Honestly, we're talking 5 minutes and five bucks. It's the cheapest insurance I can provide for my instruments. My instruments are exposed to a wide variety of environmental conditions. I do many things that other builders may think is a waste of time in order to ensure that my ukes are as bullet proof as they can be without compromising tone. Many of these things I won't talk about. (Sorry). I NEVER want to see one of my ukes come back to my shop for repair due to my neglect.
 
I guess I haven't seen enough failed necks to convince me... also, CF is pretty much a non-product here in the UK so it just doesn't occur to me.... I'll be putting one under tension in that Terz guitar I've been building for the last 3 years tho - seen plenty of bent guitar necks. :)
 
It seems like a no-brainer to follow Chuck's lead on this. But if he thinks he's going to talk me into wearing a tutu, well....
 
Thanks, imabuddah. Steel, huh? I wonder if Collings uses reinforcement in his ukes?
 
Pete Howlett said:
... also, CF is pretty much a non-product here in the UK so it just doesn't occur to me....
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Depends on where you look Pete. There is plenty of it in use in the UK. Your local lifeboat is made of it, for example. :)

However, strips can be got through the model-making sources, especially the model flying ones. I've used it in a couple of instruments in a T configuration, but also as a back reinforcement plate around unusual sound-hole shapes.

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Here's another take on the binding machine. The arm came out of a storage room at work. It was part of a monitor support that was left over from the bad old days of CRTs, so it can take lots of weight. There must be a million of these still around for the taking.

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The underside of the laminate trimmer uses the usual tapered donut that rides on the rim of the uke.

Hold-down is done with a vacuum pump at about 20 psi. The three fixtures can be positioned for any size uke. A small radius dish is used to get the correct angle so the fixtures will seal to the base and the uke. This also allows the uke to be leveled by sliding to the right spot on the radiused base. The hold-down offered by this arrangement is very firm.

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Most importantly, it works fine and cuts a nice, smooth ledge.

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It didn't hold all that well to the bare wood - the air could be heard rushing through the pores. So, the first fill coat of epoxy was applied to the back and sides to get a good seal.
 
I want to be able to buy 3/8" square rod in the UK... I've laminated my own from 10mmx1mm strip but the fuss!
 
sweet! where did the vacuum modules come from? The white things with the gaskets..
 
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