Crystal Heart ukulele

[dekutree64 713]

Get ready for something unusual! A hand built ukulele decked out in pony imagery. A while back I promised to do thread documenting the build process when I got around to making it, so here it is

 

Here are the woods I'll be using:

 

It all started when I saw that back/side set on a guitar wood site I buy from periodically. The two spikes, with heart-ish shape in the middle... remind you of anything?

 

So, I decided it had to be built, and bought the set. For the main soundhole rosette inlay design, I'm actually going to be doing the changeling launcher scene from Canterlot Wedding. Only one episode before Crystal Empire, and the heart is Cadance's cutie mark anyway The image is just perfect for a rosette. So here's the plan:

 

The soundboard will hopefully be that pinkish colored wood in the first image, which is giant sequoia. Hard to come by, and the guitar size set I had was extra long, so I took the two offcuts and glued them together lengthwise... look closely and you can see the seam across the middle. Normally you take two long, narrow pieces and join them up the center, so this is a bit unusual. Joining this way isn't particularly strong (although it's scarf joint at least... not straight endgrain to endgrain), but the line will be around the narrow part of the waist. Being a mostly inactive area acoustically, I can glue some reinforcement wood inside that won't show or hurt anything. And from the outside, the seam will be mostly hidden by the inlays and soundhole. Always good to save rare woods from going to waste

 

The neck has a bit of work in it already. Starting from a straight stick of wood about 2"x3/4"x24" or so, I saw the end off at an angle, take the piece, flip it around, and glue it to the underside (with some cleanup of the rough sawn surface, of course)

 

And take two pieces 2" long, glue them together to make a heel block, and glue that on to the neck.

 

Then, the design for the headstock. Again going unusual, normally the grain of the headplate would run the same direction as the neck. But I had this little rosewood offcut which has a nice gradient from light to dark, and reminded me of the night sky when turned sideways... and then inspiration struck: aurora borealis!

The crystal castle makes a sort of aurora thing, so it fits with the overall theme. I think I'll do a more natural style, all cut from that one shell blank that has nice wavy reflective properties. But there is this shot:

I haven't actually cut the pieces yet, so I could use different materials to make it more multi-colored like that, but I'm not sure if it would be as... aurora-y-looking. Especially to non-bronies.

[MelancholicMemory 2,027]

Ah, the noble ukulele; most masculine of all major instruments. This is an amazing project, man, and I wish you luck with it. I bet it will turn out great. Then you can have a spontaneous ukulele concert.

[dekutree64 713]

Ok, so continuing work on the neck, first I sort of cut out the headplate shape.. just the sides, since the crest is near the edge of the original piece, and I might as well do it while cutting through the whole headstock. I did scratch the markings for it into the surface so it wouldn't get washed off in this next step.

 

When gluing it on, I put water on the outer face, because the water in the glue on the other side soaks into the wood and causes it to expand, bowing outward and making it hard to get clamped while it slides around. Watering both sides equalizes the expansion and keeps it flat.

Using hot hide glue this way, you actually don't have to clamp it at all. Just press it down and rub a bit to squeeze the glue out from under it until it suctions in place. This is an old technique called "hammer veneering", although the "hammer" is actually more of a squeegee, and I just use my fingers. But it doesn't hurt to clamp it anyway,

Unfortunately, my cork lined block has a bit of glue soaked into it, and the water reactivated it... lost a bit of cork when pulling it up

But no matter, just scrape it off and continue. Next step is to saw the crest. I also chiseled the thickness down some, so I don't have to cut through quite so much wood.

Then lots of work with little files to smooth it out:

Then do the sides. Easier to carve with a chisel than to saw, followed by rasp and cabinet scraper to refine it. The scraper is one of the most useful tools ever invented... just a thin rectangle of steel, polished smooth and square on one edge, and then rubbed with a burnisher (hard metal rod) to work up a tiny little "hook" along the edge, which functions as a blade to make ultra-thin shavings. Sort of like a hand plane, but also can work on curved surfaces like the sides of this headstock. I rarely use sandpaper these days, because scraping is faster than even coarse paper, and leaves a smooth surface so you don't have to work through grits.

 

After getting the shape all done, I seal the endgrain with hot hide glue. Applying shellac to endgrain darkens it quite a bit, but hide glue doesn't. So I do this to keep that surface looking more like the others.

Then shellac the sides too, to keep it all clean while working on the rest, and it's time to cut the inlays. Or carve the rest of the neck. Not sure which I'll do first.

[dekutree64 713]

Ok, continuing on, it's time to cut the inlays! Here are all the shell blanks for the rosette, as well as a couple for other instruments:

 

Species are white mother of pearl for Shining Armor's body and paua abalone for his hair, pink mother of pearl for Cadance's body and pink abalone for her hair. Not quite purple and yellow like it should be, but it's as close as I can get in a single material.

 

Here's my tiny shop, in shell cutting mode.

 

Most of my tools are on that little table behind the lamps, and more in the box underneath. A couple saws down the crack on the lower right.

 

Rather than a normal table-style workbench, I just have a platform about 6 inches high that I sit on top of. Just enough to saw things at the edge, and with a little overhang for clamps to reach under and hold things down around the edges. Very compact, and allows the use of my feet to hold onto things, which saves a lot of time fiddling with clamps. A little tiring on the back sometimes, but overall I prefer it.

 

I came up with the design when I lived in an apartment and didn't want to build a massive bench that would be a pain to move later, but wasn't allowed to bolt things to the walls/floor, so a lightweight one would slide all over when pushing into the workpiece. This way, I'm sitting on the same surface so I can push as hard as I want.

 

Here's a closeup of the shell cutting table:

 

I really need to make a new one... the design on this one turned out to be pretty bad. And make it out of plastic, because I use water to contain the dust while cutting, so the plywood surface is all warped.

 

I like to make all the inlay patterns low-tech style. Trace the design from the original plan onto a new sheet of paper, cut out the pieces with an x-acto knife, and glue them onto the shell blanks with super glue  If I cut them accurately, they should fit together perfectly. But being reality, it took a little bit of fiddly file work on a couple pieces. Shining's hair was by far the toughest, having interlocking pointy bits. Especially since I can't get a file into the tight corners, so I have to carefully scratch at it with the jeweler's saw if I need to work in there. But I got a decent fit in the end. Here's the whole pile, ready to be super glued together and then inlaid into the soundboard.

 

I also cut the pieces for the headstock, but they still have the pattern paper glued over them so they're not much to look at. I'll be inlaying them soon, but first did some more work on the neck. Drilled the pilot holes for the tuners, and thinned down the headplate some.

 

Then saw slots into the heel for the sides to lock into. I do this in two passes. First one freehand, then stick a scraper into the slot as a spacer (it just happens to be the same thickness as this saw cuts) and saw again, gently holding the blade against it to double the slot width.

 

Then saw the neck taper, do a bit of rough carving, draw the heel shape, and make a few rough saw cuts to begin approaching the final shape.

 

Next up will be lots of chisel and knife work to refine it, followed by scraper/rasp/sandpaper to smooth out the tool marks. And the headstock inlay.

[Cygnus 60]

I'm not sure if it's madness or brilliance that drives you.

[dekutree64 713]

I'm not sure if it's madness or brilliance that drives you.

Probably a little of both. And a lot of ponies

 

I took a break from this build to finish up this other one that I'd been procrastinating on all summer:

Well, it's still not done done, but it's fully playable now. 13 string harp guitar, with halloween-ish inlay theme

 

But now, back to work on the neck!

Rough carve with knife and chisel. Not much to it, just chop away with a shape in mind, and make sure to always keep your fingers out of the path of the blade for safety.

 

Then carve the headstock end to near-final profile.

 

Use a spokeshave to connect the two profiles. Basically a really short plane, just enough of a sole to keep the surface pretty much flat, but can work in tight spaces like this.

 

This wood doesn't really carve that well. It's soft and doesn't take much force, but on endgrain surfaces like the heel, the knife kind of chatters and leaves a chewed up surface. Had to switch to a rasp to do the final shaping.

 

Then file/sand/scrape smooth. Looks reasonably symmetrical. Unfortunately, the wood grain doesn't match perfectly.

 

I just don't know what went wrong. It looked like it was lined up correctly when I glued it, but maybe it was impossible because this piece has a bit of runout on the surface that's joined here. I'm also not really happy with how visible the glue lines are. Guess I need to scrape smooth after sanding the joints... or better yet, work on my hand plane skills and skip the sanding entirely.

 

Next I started refining the headstock, scraping a hollow in the back, as I like to do when using peg style tuners. Unfortunately I went a little too far and thought this was just wood grain, but actually I scraped right through the headstock piece and into the neck piece Oh well, there's still more than enough joint area, so it's pretty much only a visual blemish.

 

Then drill the holes larger, and ream for the tapered tuning pegs. These are planetary geared pegs, so more accurate tuning than usual friction pegs, but only 4:1 gear ratio which I like better than high ratio machine tuners. They're really light weight, too.

 

So here's the current state of the neck. Still needs some more refining, but the basic shaping is done.

Ok, after some more scraping, sealing the heel endgrain with glue, applying shellac, sanding with 400 grit, and applying more shellac... here's the neck looking all nice and shiny.

 

And with the tuner holes being properly sized, I can finally inlay the aurora pieces. Had an order dependency there because of the one that goes "behind" a tuner.

 

First I stick them in place with a couple dots of elmer's, and scratch a little line around the edge of each piece with this scribe (essentially a large and sturdy needle)

 

Then pop the pieces off. The scribe marks aren't all that visible unless you get them in the light right.

 

Then route out all the wood inside the scribe marks with this Dremel type tool, with a router base attachment. I don't like using power tools, but there's really no hand tool substitute for this one. I'd have to use a different approach for things like this, where you stick the pieces to the headplate before gluing the headplate to the neck, and saw around them with a jeweler's saw. But inlaying small/thin/curvy/pointy shapes into some parts of the guitar would be more or less impossible, so I just put up with the noise/danger/mess/uncoolness

 

I use a few different sizes of end mill bits. Mostly 1/16", but also 1/8" for large middle areas that don't require accuracy, 1/32" for tight spaces, and recently added to my arsenal, an itty bitty 1/64" bit for pointy corners. I still jab at the corners with a knife to bring them to a full point, but the new bit means less wood to remove that way, which is nice when working with really hard woods like this.

 

Then lots more fiddy file work to fit the pieces to the edges of the headstock (and that tuner hole). I prefer to do it before I glue them in, so I can use water to contain the dust. Then fill the pockets with hide glue, press the pieces in,a nd wipe away the squeeze-out

 

The paper towel stuffed in the tuner hole is just to keep glue from running down in there.

 

The pockets are a hair too deep, so it will require leveling, but not much. Should look better once i get the surfaces polished and shellacked, but I'm not sure it will ever photograph that well... abalone shell is most beautiful when you can turn it and watch how the light reflects. I'll make a video when it's done.

 

Then glue the rosette pieces all together. Ended up needing a little bit of file work on a lot of pieces. Start by gluing arm to body, then those next 3 pieces had to go all at once due to all the edges that needed to be in contact and angled properly relative to eachother. Ended up having to use a toe to keep his body in place, one hand to hold the pieces, and the other to drop some superglue on it.

 

Then just keep adding pieces, filing to fit as needed.

 

And they're done!

 

And a cute shot more like their position in the show

 

They still need to have their eyes and Cadance's wing engraved, but that will have to wait until they're inlaid and leveled.

 

Then I planed and scraped the soundboard surface smooth, and was debating whether to shellac it straight away or seal with hide glue first. I decided on glue, because it may keep it a little lighter colored, and because of that seam in the middle that should be more invisible if the rest has a coat of glue as well. I decided not to thin the glue with water first, in hopes of it not soaking in and darkening as much. Unfortunately, the relatively thick glue layer was strong enough to pull the wood with it as it dried and shrank, resulting in this:

 

Normally you'd have more trouble with it bowing the other way due to the water from the glue soaking into the wood... but I guess my idea to keep it from soaking deep worked

 

Fortunately after scraping most of the dry glue off today, it flattened back out for the most part. I think I'll give it another round of glue, this time thinned with water, and finally shellac, cut it to shape, thin it down until the flexibility feels right, and inlay the rosette.

[dekutree64 713]

So, after getting the soundboard back flat, it's time to thin it down to probably-final thickness, cut it to shape, and inlay the rosette.

 

After some work with my trusty block plane to thin it down, I mark the pattern.

Due to lack of a centerline, I used that little ruler to get perpendicular to the horizontal joint line, and then mark where I put the pattern with the tape bits for when I flip it over and do the other half.

 

One fun thing about using really soft woods like this is that you can cut out the shape with an x-acto knife instead of a saw. Takes quite a few passes, but I think it's still a little easier.

 

I decided to test the strength of the joint line on one of the offcuts. Being about a 30 degree angle, I don't expect it to be as strong as the wood, but strong enough to hold together with some reinforcement...

Well I'll be darned, it really is stronger than the wood! Hide glue is some amazing stuff... and my jointing skills too, apparently  I'll still give it some reinforcement, but it looks like it won't be strictly necessary.

 

The trick to using hide glue when endgrain is involved, is to first seal the endgrain with glue. Hide glue sticks to itself, and can be reactivated with heat and water, unlike modern synthetic glues. In this case, I did it in a sort of roundabout way. Back when I first joined it, I flexed it to feel the stiffness, and the joint popped apart cleanly. I figured it was because of the endgrain sucking up the glue and starving the joint, so I reglued it. This test indicates that I was right, and it's much stronger this time.

 

Next, poke a hole to mark the soundhole center, and go looking for a round object that's about the size you want it to be. I ended up with a spool of wire. Scribe around it for now, and later I'll cut the rest of the way through with the knife, like I did cutting out the shape.

 

With the soundhole marked, I can position the ponies and heart, and stick them down with a couple dots of elmer's glue. Scribe around, pop 'em off, and then reassemble Cadance after her legs fell off

 

Inlaying into softwoods requires one more step before routing. I go over the score marks with a knife, pressing in to cut the dark grain lines. They're a lot harder than the light wood inbetween, so the scribe bumps over them, and leaves a sort of dotted line. Same happens when you take a router to it... tends to chatter as you cut through the alternating lines, and is harder to control. Cutting with a knife makes for a nice clean edge and easy routing.

 

Then rout out the wood inside the lines. I made a few passes, deepening them just a little bit at a time to get almost exactly the same as the thickness of the ponies. Unfortunately I had a little slip, so Shiny's chin will have a small gap below it. I hate not being perfect

 

Then glue 'em in. Next mishap, the plane I left sitting on it to hold it flat left a black stain, due to the water I used to clean up some glue there. Hopefully it will scrape out.

The gap is pretty unnoticeable. Plus Cadance ended up with a gap by her upper tail piece that's even more noticeable, and a couple around her hair as well. Not sure what happened there... maybe when I reassembled her after the marking step, I got her lower half slightly misaligned. Now that I think about it, I may have enlarged the pocket just a bit to get her to fit in there... should have done the test fitting with the separate pieces before gluing her back together. Oh well, it's still a nice fit. Just not quite the level of perfect I wish I could do

 

Then scrape level. Ended up taking a bit more than I expected, but that was partly due to bringing the shell down along with the wood to get that black stain out. It wasn't deep, but did require scraping through the shellac and glue finish on the wood.

 

Next I'll redo the glue sealer and shellac on the wood, polish up the shell (and a bit of surrounding wood) with fine sandpaper, engrave the eyes/feathers, and cut out the soundhole.

 

Oh, and I also finished the leveling and polishing of the headstock. It actually does photograph well now. Shiny

But now the question is, is it actually recognizable as aurora, or do I need to add a black mountainy horizon at the bottom?

[dekutree64 713]

Not much to report, on account of laziness as well as spending more time on other projects than this one. I still haven't made up my mind for sure, but I think I will add some ground to the headstock.

 

All I've actually done is finish up the rosette. After getting it all leveled, I scraped all the old finish off, re-applioed the glue coat, then cleaned the glue off the inlays with a bit of water, and polished them up.

 

Then finally, time to make my first attempt at engraving! After practicing a couple times, I decided to use a knife rather than a proper graver. It makes a thin scratch, but I feel a lot more comfortable pulling than pushing. Fortunately there were no big disasters, but my lines did come out just a bit squiggly But they'll do. Then scrub some engraving filler into them (basically a big black crayon), and coat the whole thing in shellac. Here's a closeup of Cadance's engraving (eye and feathers)

 

Then cut out the soundhole, round over the edge, and slop some shellac on. I was scared for a while, because the alcohol in the shellac wicked into the endgrain and looked like a mess at first:

 

But after drying, it's all evenly colored again. So here's the finished soundboard surface, ready for bracing, which will be next.

 

I'll have to scrape away some of the finish at the end to glue the bridge, but this is more or less what it will look like on the completed instrument. I love this finish. Shiny, but not too shiny, and with some natural wood texture to the surface. It begs to be touched, unlike the typical ultra-flat mirror gloss that begs to be wiped clean and hung on the wall And luckily, it's really easy to do, doesn't need any special tools, and is non-toxic. Doesn't protect the wood from being dented if you smack it into things, but then any finish thick enough to do that will also hurt the sound a bit.

[Kallarmo 6]

This is just amazing! My mouth dropped open when I went through the pictures. I have no experience in woodworking or instruments at all, but I'd say anyone who saw your work would be stunned! I know I am!

 

I must say I wonder the same as Cygnus. This is absolutely brilliant! Can't wait to see how it turns out in the end!

[dekutree64 713]

Got a lot done today! Largely because I decided to skip sleeping before the new episode and had nothing better to do

 

I was actually doing all this stuff concurrently, between glue drying on each thing. But I'll sort the pictures by task so it's less confusing

 

First, got the headstock inlay really finished up. Cut the ground piece, sand the edges to fit the headstock edges precisely, and thin it down... which was rather difficult, since African blackwood is insanely hard, and the piece I cut this from was pretty thick so there was a lot to remove. I did most of it with my trusty 1/2" chisel, cutting across the grain. Also drilled an undersize hole in the approximate location of the tuner hole. Score around it, and router it out.

 

Then glue it down, with water on the surface to keep it from cupping, and a few clamps, similar to gluing the headplate earlier. After it finished drying, it was still much too thick, so I decided to go with coarse sandpaper to grind it down.

 

I was trying not to hit the upper part of the headstock so I wouldn't have to re-level and polish the whole thing, but unfortunately I did scratch the auroras and had to do the full routine. Then carve the tuner holes out to full size with a knife, give it a couple coats of shellac, and I'm definitely glad I decided to go through with the addition The dark horizon really highlights the gradient from light sky at the bottom to dark at the top, just like I wanted

 

Then it's time to get the soundboard braced, and neck glued on! First of all, I need to cut the ledge in the neck where it will fit onto the soundboard, with the outer surface being level with the fingerboard gluing surface. Traditionally this is done with a chisel, but I was feeling lazy and decided to use the dremel router. It makes such a nice consistent depth that's hard to do by hand, and I don't have a chisel properly sharpened with a perfectly flat back for this sort of flat surface work. I went in a few passes, since the soundboard is pretty thick so there was a lot of wood to remove. Leave the outer edge for last, as well as a couple platforms, for the router to sit on.

 

But in the end, they're all routed away, leaving a nice level ledge.

 

I actually had to sand it a bit after that, because I got the router depth a hair too shallow for the soundboard thickness. Similar sanding setup to the inlay leveling, except with the sandpaper edge right at the edge of the bench, and neck hanging off the edge.

 

The soundboard braces are made from offcuts of the same piece of wood as the soundboard itself. It was quite thick when I got it, and mostly flatsawn near the outer edge, therefore quartersawn when turned upright as braces (which is generally preferred).

 

Glue the first one...

 

Then another offcut thinned down for the bridge patch. I usually don't use bridge patches, but since this soundboard kept wanting to curl inside out, I needed to glue something across under here to coax it into a convex shape. Plus this wood is really flexible across the grain, so it would be better to use a wider bridge than the butterfly design... but this works too, using an internal brace to effectively widen the footprint.

 

Then glue the neck on (after trimming the soundboard end to align the neck with the intended bridge location), and glue the last brace, which is simultaneously glued to the endgrain of the neck (which is why the neck needed to go on first), and here's the current state of things.

 

I still need to carve the braces down some, and I'll be shaving a lot off of the bridge patch. I may add some reinforcement patches under the rosette as well. Probably not necessary, but everything above the middle brace is more or less acoustically inactive anyway, so it shouldn't hurt anything.

 

After that comes the dramatic task of side bending!  Hopefully the ziricote side wood won't live up to its nickname of Mexican crackwood :okiedokielokie:

Edited December 30, 2013 by dekutree64

[MissShiningStar 33]

Amazing! I can't wait to see the finished product!

[dekutree64 713]

Unfortunately, the side bending did not go well at all. First, the Mexican crackwood did indeed live up to its name even before bending. There was a long crack in one of the sides, as well as some small cracks around the knot in both. I decided to go with super glue to repair, because hide glue separates with water and heat, which are needed for bending. Unfortunately, it stained the light colored sapwood pretty badly, so you can see it even in this low resolution photo (circled)

 

I decided to go ahead and use it anyway, because I hate to waste wood, and it really doesn't look that bad, just... visible. If it was a natural grain feature, I'd probably think it was cool

The knot was another problem waiting to happen, though. I trimmed the sides as narrow as I could, to remove some of it. But there was still enough endgrain (including some that had already cracked and been glued) that I was afraid would fail anyway. I calculated that it should end up just below the waist though, where the sides are relatively flat, and thus won't be exposed to too much stress during bending... hopefully.

 

Here's my side bender... just a hunk of exhaust pipe, free from the scrap bin at a muffler shop, bolted to a piece of wood, which I screw to the short wall in my room. Then shove an electric charcoal starter in to heat it.

 

Not the most fire safe setup, but I used it outdoors for a long time before deeming it safe enough to work indoors. Nowadays I only do this assembly phase during the winter when the humidity is low, so it's not really even possible to bend outside unless I catch a lucky warm day.

 

First bend the waist. I put it above the knot, as my calculations showed. Normally I would have gone quite a bit lower, to make sure there was plenty of length above it, but that would have put the knot right in the middle of it and almost definitely would have broken on such a tight bend (as tight as I can get on this fairly large diameter pipe... and still not actually quite as tight as the design calls for). This is where I made my big mistake...due to the inability to get the bend as tight as the pattern, I ended up putting the waist even higher than it was supposed to be, trying to stay away from that knot.

 

Then bend the shoulders. This is where I should have noticed something was wrong, but didn't. There's way too much space between them for the width of the heel on this instrument. Would have been ok on some guitars, and I'll claim that as my excuse,. But really it was just ignorance, blindly believing my calculation was right.

 

Then bent the rest. I hope this gets easier one of these days. Still takes me forever to get them reasonably close to the pattern It's a tricky balancing act of heat (either plug the charcoal starter through a dimmer switch, or just unplug when it gets too hot and plug back in when it gets too cold), water (I use a spritz bottle, as well as a wet paper towel on the pipe), and pressure (I use my bare hands, and sometimes a wood block pressing it flat against the pipe to prevent cupping of flatsawn woods like this).

 

And now for the really stupid part, I trimmed them to length before I noticed the heel issue. So now I can't even adjust the bend to try and put the waist closer to the knot without breaking it. These sides are unusable for this instrument I could probably use them on a different one, making it slightly narrower and with a wide, flat heel instead of the tapering style on this one. But there's still that glued crack (which separated in bending and had to be re-glued, so it's even more iffy to use), and some ripples due to the wonky grain in the knot area... I'll probably just declare them dead.

 

Fortunately I have a guitar set with wide sides, which I may be able to pillage from. If not, then I'll have to go hunting for some replacements...

 

I did some other stuff too in preparation for assembly, but I'll post that next time. And before that, I'm going to see if I can whip out a Flutterbat plushie real quick, because cute

Edited December 30, 2013 by dekutree64

[StrawberryTasu 61]

omg.... I. LOVE. IT!!! It's amazing

[Metemponychosis 1,263]

This is so great.

Human craftsmanship + ponies = 

Kudos to you.

[dekutree64 713]

Well, I still haven't gotten around to bending the new sides, but that guitar set I had in mind does indeed have enough width to spare... and some large cracks at the ends, so I may not be able to use it for guitar sides at all. Not one of my favorite woods, but it certainly does look cool.

Here's the Flutterbat plushie I was working on for the past few days

http://dekutree64.deviantart.com/art/Flutterbat-plushie-424492752

 

And here's the stuff I did before that, which I may as well post now since I'll be hiding under a blanket for the next couple days until it gets above 10 degrees outside. Low tonight is -8, with 21mph wind I feel like Philomena with the ice pack.

 

So, first, carve the soundboard bracing and trim the ends to fit the pattern:

 

The bridge patch is quite thin, mostly there to hold the arch. Still adds a bit of stiffness, but don't want too much.

 

And then make the lining blocks, which nobody can ever agree on exactly what they're called. I say dentellones, others say tentellones, the Spanish say peones, and there are various misspellings that I'm pretty sure are wrong. I've heard that the word originates from the fact that they look like teeth, so probably the same Latin root as dentine/dentist/etc, hence my chosen spelling.

 

They're just little triangular blocks of spruce, most of which are rounded on the back to mate with the concave areas of the sides. For the waist, I just use narrower flat-backed ones, because it's easier than sanding a concave surface into them. I made these from some soundboard offcuts I had lying around, and the process involves a little bit of sawing, and a lot of sanding and splitting with a chisel.

 

Then make a tail block, which acts as a gluing surface for the sides, as well as an anchor for a strap pin, although I don't usually install them. Not much to it... just part of the neck offcut, planed to thickness, sanded to the curve of the sides, and rounded over some on the inner surface so it's thick enough in the middle to be strong for a strap pin, but the top/bottom glue surfaces are about the same width as the rest of the linings, so it doesn't cut into the main vibrating area.

 

All prepped for assembly, just as soon as I get those new sides thinned down and bent. It's a little tempting to make a new side bender first, with a smaller pipe so I can bend tighter curves. Although I'd need a different heat source, since the charcoal starter fits tight in this one. Or maybe I can find a thin walled pipe that I can mash into an oval shape, thus having a wide direction for the charcoal starter, and a narrow direction to allow tight bending.

Edited January 6, 2014 by dekutree64

[dekutree64 713]

GUESS WHO'S BACK

Sorry for the long delay. The day after the side bending disaster, the temperature outside dropped like a rock, and with it went the humidity. Too low for assembling instruments, or they might pop glue joints if taken to a really humid place later. But on the other hand, if you assemble in high humidity, they'll crack if dried out. Around 35-40% is best. and at ukulele size, should hopefully tolerate just about anything other than rain or a hot car.

Usually I build in the winter because the humidity is low, and there are occasional good glue days. But this winter was very long, and freezing cold the entire time... barely ever got to 25% humidity. It was also just too cold to work in, so I ended up waiting it out.

After a couple weeks of finally being in the 25-30% range, I decided that was close enough and I'd get going again... so naturally it jumped straight to 50% during the time I was bending the new sides  But by then I was in too deep, so I had to go ahead with the assembly. Only the side braces really need good humidity though, and it should be back down in a couple days, so I can put that part off until then.

So here are the pictures:

First, the new side set. I cut these off of an oversize guitar set. Better quality than the old ones, although there are still a couple tiny knots. Should be fine though. The color should match perfectly once the sides have a coat of shellac like the back.

Several hours of bending later (somehow this never seems to get any faster or easier...), and lots of measuring before cutting to length, they're not quite perfect (as you can see by the small gaps of light under it), but close enough.

Then scrape the inner surface smooth and clean.

Glue the sides to the tail block. Technically this should use a curved caul, but I wanted to try to get a near-invisible seam at the tail, and it's hard to do it with a caul blocking the view... so I devised some silly clamping setups, springing the sides to get a little more pressure on the block.

 

Then drop some thin superglue on the inside where the knots are, to make sure they're good and solid. Looks like these two actually did split during bending, but are just so small that it didn't cause any significant kink in the bend. They kind of look like eyes now...

 

Then comes the real fun, gluing the sides to the soundboard. Lots of little lining blocks to glue, one by one (takes forever, especially if you forget to mix up two bottles of hide glue so you can use one while the other warms up in the glue pot)

 

All done. There will be 6 side braces. 4 that sit on top of the brace ends, and two in the spaces I left open.

 

Finally it's starting to look like an instrument!

[dekutree64 713]

Ok, after an awesome thunderstorm, it's winter again, and thus the humidity is back down. Fortunately it stayed in the 35% area long enough to let the wood acclimate for a few hours and then get the side braces glued. But before that, I trimmed the overhang on the soundboard. Just chisel and finger plane around:

 

Sometimes you can get some really pretty wood chips:

H

 

So here is the final body shape, also with the fingerboard blank I'm probably going to use (ziricote, like the back and sides). It came out pretty darn close to the plan, and probably the most symmetrical instrument I've ever made 

 

Then taper the box depth. The tail block is taller than the neck heel, and sides are tapered to go between them. But not actually perfectly flat, because the back will have a slight dome to it, and I want the rim to match that. Many builders use a sanding dish to do this, but I'm too much of a cheapskate to buy one, plus I have very little space to store things like that. So first I aim to get the rim flat, but about 1/16" or a bit more above the heel and tail block height. After several rounds of trimming and checking against the work surface, it's looking pretty good:

 

After that, draw a line around the sides, 1/16" down from the edge, and use that as reference to plane a smooth curve from the highest point at the waist, down to being flush with the heel and tail block. Doesn't have to be perfect, as long as it's relatively smooth. The back can flex a little when gluing it on.

 

Once that's done, I can do the side braces. I cut them to precise length, so they end right at the edge of the tapered sides. Here's the shop in side brace making mode:

 

I make them out of old soundboard offcuts. Cut to approximate length, split off a stick with a chisel, plane it smooth, sand the end square on my trusty extra-extra-coarse diamond stone, then hold it in place and mark the height of the side where it will be, saw at the line, sand to perfection, and on to the next one. Then glue 'em in two at a time, because that's all I can manage without the bars on the clamps running into eachother I need to find some better clamps for this job.

 

Then make some kerfed linings for the back. Using more old guitar soundboard offcuts, split off a strip, plane it to a nice curved profile, saw a bunch of little slots in it so it can conform to the curves without heat bending, and snap off however much you need to glue between each pair of side braces:

 

At least, that's the theory. But it's tricky to saw just the right depth, and I kept accidentally going through and ending up with shorter strips. But that's fine. Just a little more work fiddling with 2 or 3 short strips per section. Also my saw is a little too coarse for this kind of work, and spruce is kind of frizzy wood, so they look a little rough. Some people are really picky about the inside of the box looking perfect, but I don't worry too much about it.

 

Next up, I need to trace the shape onto the back, cut it out, thin it down, brace it, and glue it on.

[dekutree64 713]

Well, I've kind of been chasing my tail the past few days, making new mistakes, fixing old mistakes, and lots of fiddly work.

 

1. The back rim had a slightly low spot, so I had to carefully bring down the surrounding area to match, and blend it into the surrounding curves (lots of sanding with a wood block to get it near-flat).

 

2. Made the fingerboard, but turns out I was looking at the wrong column of numbers on my fret position chart... so the slots are cut for a 1/2" longer string length than they should be. I'll save it for a future instrument, and make a new one for this.

 

3. Turns out Cadence is down slightly too low (don't know how I didn't notice that sooner...), plus the neck was tilted just a hair toward Shining's side, which made things look very asymmetrical with the fingerboard in place. Fortunately, the neck was still a little on the wide side, plus for playability reasons it's better to have the neck tilted a touch toward Cadence's side if anything, so I carved on the neck some more to do that. Still doesn't look perfect, but much better than it was, and as good as it can get considering that the real problem is the position of the inlay.

 

4. Carving off the width of the neck left the headstock looking fat on one side, so I removed a little width from that as well.. which now leaves the tuner holes slightly off center, but it'll do.

 

So, with all that taken care of, the humidity finally got to the good bracing range again, so I braced up the back.

 

First prepare the brace blanks. I just pulled these from my pile of extras from previous guitars, but when making new ones I start with a larger board, and split it along the grain with a chisel and mallet. That lets me see the orientation of the wood grain, so I can make it parallel to the plate for maximum strength. After splitting, plane them down to final dimensions, plane and/or sand an arch along the glue surface (the back should be slightly domed, about 1/16" higher in the center than at the rim).

 

Then notch the linings for the brace ends, and fit the braces into them:

 

Then put a drop of hide glue in the middle of each one and hold the plate on them for a minute. Don't want it to really dry, just get a decent grip so I can pull them up and mark where they should be glued (tiny pencil marks at the ends of the braces)

 

Then pull them off, and glue for real. Note the strips of wood underneath the plate, which help distribute clamping pressure since the plate itself is quite flexible. The strips are flexible enough to conform to the arching of the braces, but it takes a little pressure to do it.

 

Then add the center seam reinforcement strips between the braces (another use for old soundboard offcuts), which aren't entirely necessary, but good insurance. Then carve the braces to triangular profile, which removes a lot of weight without removing a lot of stiffness.

 

And then start shaving on the height of them until it sounds and feels good (holding it up lightly between two fingers and tapping it, and flexing it with my hands).

 

Once I think it's good, I clamp it onto the box and tap on the soundboard to get an idea what it sounds like all together.

 

It's not a sure reading on what the final box will sound like since the clamps are so heavy and make it sound lower pitched. But the relationship between the top and back resonant frequencies seems to stay pretty close, so it's a good way to tune them together. Usually you want the back to be a little higher frequency than the top. Adding the bridge will also change the top frequency, and I may actually do that before gluing the back on incase I want to change the back braces as a result... but I haven't decided for sure yet, and for now it sounds pretty good.

 

Next up I'll make the new fingerboard, and the bridge.

[dekutree64 713]

Ok, finally got the new fingerboard done.

Thin it down to 3/16", cut it to match the neck taper, but a little narrower to leave room for some decorative strips, draw a line down the center, and another line perpendicular to that. Use that line to position the ruler that will be used for marking the fret positions. Clamp it down, and give a little poke with an x-acto knife for each one. My chart is getting pretty crowded Each column is the fret positions for a different scale length that I've built so far. The way I ended up messing up the old fingerboard is that I was looking at the last column, when I really needed third from last -_-


My ruler (actually graduated straightedge) is in 64ths of an inch, which means that if I put the knife half way between two marks I can get them accurate to 1/128". I actually try for 1/256", but it gets kind of iffy at that point. It's convenient to be nearsighted for this

Repeat the marking process two more times so there are marks down the left, middle and right of the board. Really only need two sets of marks, but I like to have the third set for error checking. Then clamp a wood block at each set of marks, and gently hold the saw against it while cutting.


Here's what it looks like lining up the guide block with the marks. This is the old fingerboard, since I forgot to take a pic of it on the new one, but the marks are more visible on the lighter color anyway... and even then you have to zoom in to see them. Tiny little black notches, just a hair's width above the edge of the block. Cutting the fret slots is the part of the instrument that requires the greatest accuracy of work. Especially on a small instrument like this where the frets are close together, being off by 1/64" would probably be pretty out of tune.


Then glue on the decorative binding strips, which I cut from the outer edge of this curly koa guitar soundboard set. It's quite a bit wider than necessary for the guitar I'm planning to build with it, so no harm nibbling material from it And it's 3/16" thick, which is conveniently the same as this fingerboard.

So here's the fingerboard in place, showing the frustratingly out-of-place inlay. It actually points a little toward the right, as you can see by the soundhole. But it's still obvious that Shining is up higher than Cadence, and there's nothing I can do to hide that

 

In other news, I've been taking some inspiration from Maud Pie and collecting rocks while out hiking lately There's a place nearby (right here https://maps.google.com/maps?hl=en&ll=38.988068,-94.511347&spn=0.014093,0.033023&t=h&z=16) that has pretty blue-gray rocks with tan edges, as well as red rocks. I look for small, thin bits that are easy to grind down to suitable thickness for inlaying into instruments. Despite the viewing angle, this red one is not thin, but it was just too pretty to pass up Luckily it's pretty soft so I can probably saw it into slices rather than having to grind forever.

[dekutree64 713]

Well, I'd originally planned to make the bridge out of walnut, but upon digging through my box of scraps, I found a piece of rosewood just the right width and thickness for it, so I decided to use that. Matches the color of the fingerboard better too (although they're actually different species). But then I thought, maybe the original bridge design in this wood would be too heavy, so I decided to try designing a smaller bridge, using a different string anchoring method (where you tie a knot in the end of the string and slip it into a slot in the bridge, rather than the classical guitar style tie block). Then I couldn't make up my mind between the two, and the piece of wood was just the right size to do both, so I decided what the heck, I'll just make 'em both and then decide. Whichever one I pick will get some shiny shell inlays in the wings, but that's too much trouble to do twice.

 

Step 1 is the saddle slot. I do this with my Dremel-type tool in a router base. First drill holes at the ends of the slot, and route inbetween. Here's my ridiculous looking setup. I never bothered to make a proper saddle slot jig, so I rig up something new every time out of whatever clamps and random objects I have lying around Really the only part that matters is that the ruler is clamped to the wood right there so I can slide the router against it. The rest is just shimming up to give it a stable surface to sit on. A day may come when I'm able to do this with a chisel instead of the router, and still get the bottom of the slot perfectly flat... but it is not this day.

 

Sometimes I cut out bridge shapes entirely by jeweler's saw, but other times it's easier to carve everything but the endgrain. So here, I've cut out the ends of the wings by saw, and then clamped it vertical so I can carve the top edge with a chisel. Jeweler's saws weren't really meant for cutting thick stuff like this... and especially oily woods like this, which gum up the teeth. Much quicker this way.

 

Repeat for the other bridge, although this one I routed the saddle slot all the way across rather than drilling holes for the ends, as is the common approach for tie block bridges. Then saw the hunk of wood in half, and repeat the edge carving technique for the bottoms of the bridges. I also sawed the string slots in the little one.

 

Then carve out some pockets underneath the string slots. This is the underside of the bridge (the saddle end holes are drilled all the way through, although they don't really need to be). The string knots will go under here, and not be able to fit through the slots, thus anchoring the strings in place.

 

Then thin down the wings and smooth over the top surface with a chisel and scraper and sanding block, and it's as done as it's getting for now:

 

Then chisel a ramp between the saddle slot and tie block on the big bridge, drill the pin holes (all perfect ), thin down the wings, and it's done too:

 

And surprisingly, they're the exact same weight at 6 grams Plenty light enough, so it's just a matter of which one looks better I guess. If anyone is reading this, let me know which one you think is better

[Bolt the Super-Pony 62]

I think they both look amazing. Awesome and inspired designs! Great job!

[dekutree64 713]

I think they both look amazing. Awesome and inspired designs! Great job!

Thanks I decided to stick with the original tie block bridge. Cutting out the inlay pieces was just the usual routine... trace the shapes from the plan, cut them out with a knife, superglue to the shell blanks, saw to the line, smooth the edge on the diamond stone. Then position all of them, poke holes at the center of where the dots go, and scribe around the big pieces. Drill the dots, and rout the big ones.

 

Had to rig up another silly router setup, to provide a platform for the router and hold the bridge in place. There's a wood block under the bridge to raise it up some, and the diamond stones are just there as spacers because the bars on the clamps are heavy and tend to tip that direction. I also dragged everything over to the edge of the table from this picture and clamped it down, for more stability.

 

Routing went well. No significant gaps. All ready for glue:

 

And glued in, with a good slopping of glue on top so any gaps will be filled. Usually I like a small visible seam around pieces, but for this I think it will be better perfectly smooth.

 

Although now that I think about it, I probably should have used epoxy for this. Hide glue doesn't actually stick to shell all that well, which is normally fine, but in the case of the bridge, it will have the strings twisting on it, and soundboard expanding and contracting when the humidity changes, flexing it into more or less of an arch. Could potentially stretch the pockets out of shape enough to pop the pieces out. Probably won't happen, but it's something to bite my nails about for the next couple years And they can always be glued back in if it does.

 

I glued the fingerboard position marker dots while I was at it. I love turquoise:

 

The only really difficult thing left to do is the soundboard binding. I want to use curly maple, which will go with the curly koa fingerboard binding, but getting it to bend so tight for the waist will be a challenge, because curl splits easily. Maple also doesn't bend until it's almost hot enough to scorch, and is light colored so any scorching sticks out like a sore thumb I need to decide on a backup plan if I break too many pieces. Maybe just switch to straight grained maple. Or curly koa, but make it really thin so it's easier to bend, and add a curly maple veneer strip between that and the soundboard for contrast.

Edited May 1, 2014 by dekutree64

[dekutree64 713]

Ok, after much procrastination, the soundboard binding is most of the way done. Probably my least favorite task, but for once it actually went quite easily

 

But first, the finished bridge:

 

Note that the shell pieces look different than before. The patterns change quite quickly as you scrape/sand them thinner, because the alternating layers of shiny and black material are very thin.

 

One more thing to do before cutting the binding channel is to scrape the sides flat and smooth. Quick and easy, since these sides bent so well.

 

Most people cut the channel with a router and a big fancy jig to hold it vertical, but I don't have space for that kind of stuff so I do it the old fashioned way, using a tool called a gramil to score lines in the top and side, and a chisel to clear away the wood after that.

 

I decided to try a trick I learned from someone, using the square back end of the blade as a scraper to cut a groove in the sides, rather than scoring with the sharp end. You can't score very deep in hard woods like this, so it's nice to be able to cut the groove deeper without having to stop and carefully chisel away material.

 

Unfortunately, it chatters a bit, which quickly becomes a lot as the bottom of the groove develops ripples. Feels like running over those ripples they put along the edges of highways to wake people up if they start to drive off the road

 

Then score the top:

 

Make sure to always go with the grain (start at the wide points and move up or down). Note that the black part of the gramil has one flat side and one curved side. I was using the short end of the flat side to reference off the soundboard when scoring the sides. The curved side allows getting into the waist... usually. The waist on this one is actually tighter than the curve of the tool, so I ended up having to do that freehand with a knife. Delicate work! I always have to freehand the last bit going into the neck, though.

 

Then chisel away the waste:

 

Only made it half way through the soundboard this time. One more pass of score-and-chisel, and I'm through. Then switch back to "side mode", but with the knife edge this time, and score/chisel my way through the side material:

 

Then score a little more, and chisel both vertically and horizontally to square up the channel, the goal being to cut right to the original scored lines, but not past them. Still takes me a while, but supposedly you can get pretty fast at this.

 

For the last little corners that cut into the neck, I cheated and used the router. You can dig them out with a tiny chisel, but it takes a long time, and usually ends up being messier. Of course, the router could snag and make a much bigger mess very quickly, but it hasn't happened to me yet at least

 

Then bending, which is usually the worst part because it takes forever and has to be absolutely perfect, matching any imperfections in the original side bending and cutting of the binding channel. But fortunately, the curves seem to be nice and smooth on this one, plus the curly maple I'm using is actually quite flexible so it doesn't have to be as perfect as usual. It also helps that I've learned that maple needs high temperature and plenty of moisture to bend. And the way to get that, while also preventing scorching, is to put a wet paper towel over the bending iron.

 

Then give them a light scraping to smooth out the glue surfaces, and glue them in. I use hot hide glue, as I do for just about everything, which means that I have to do them a few inches at a time because the glue would cool and gel up otherwise. Squeeze some glue in, add some tape, squeeze more glue, add more tape. Nothin' to it. Also used clamps for the waist, because the bend there wasn't actually quite as tight as it needed to be, but the wood is flexible enough to conform with the clamps.

 

Give it 8 hours or so to dry, carefully peel the tape off, and scrub around with wet and then dry paper towels to clean up the dried glue squeeze-out. One of the many great things about hide glue is that it can be re-moisturized and cleaned up gently. Also nice to have the soundboard and sides with a coat of shellac at this point, so they're fairly water resistant.

 

Tomorrow I'll scrape them level and round them over. I think I'm going to give the soundboard a full French polish after that. I love the look and feel of the ultra-thin wipe-on shellac finish, but this wood is just so soft, I think it could use a little thicker shellac layer... not that that will make it super tough or anything, but hopefully enough that it doesn't dent just by looking at it.

Edited May 8, 2014 by dekutree64

[dekutree64 713]

Ok, leveling the binding. Use a handy trick, putting a bit of masking tape on one corner of the scraper so I can slide it along the side, and only hit the binding. Even more important on the soundboard, since I don't want to scratch its surface at all.

 

After getting them squared up level, I then round them over with a variety of tools (finger plane, knife, needle files, scraper, sandpaper, sometimes a rasp...). I like them pretty heavily rounded, so the edge is nice and soft on the forearm. All done and shellacked:

 

Sorry about the yellow lighting. Forgot to set my camera's white balance to incandescent after the sun went down. I think this is my best binding job yet. So much easier than usual, and no gaps at all  Usually there are at least one or two, where I have to re-moisturize and heat the glue and try to squeeze them closed.

 

After that, it's time for French polishing... which is not a material, but rather a method of applying shellac, which is the same material that I've been wiping on the surface. As they say, there are as many ways to French polish as there are French polishers. Maybe more, because I've tried several, and am not very good at any of them. The basic tool is a cloth pad, which in my case is a wad of cheesecloth wrapped in muslin.

 

You can also use wool for the core, linen or T-shirt material for the outside, or even use an artgum eraser wrapped in cheesecloth as a pad.

 

The rubber glove isn't strictly necessary, but the alcohol can be harsh on the fingers after an hour or more of polishing. Speaking of which, I don't think I mentioned before that shellac is actually bought as a bag of dry flakes (fairly thick, crunchy flakes), which you can then dissolve in alcohol. I use drinkable 95% grain alcohol (the only thing I ever buy at liquor stores, since I don't drink ), which is about as safe as it gets for wood finishing materials. The shellac itself is edible as well. It's a natural material produced by lac bugs.

 

So, starting from this:

 

I usually use walnut oil to lubricate the pad, but I've heard of people doing it with no oil so I want to give it a try. Surprisingly, it works. I actually like this better, because I can get a better feel when the pad is too wet or too dry by how much friction there is. The general mode of operation is to add shellac and alcohol to the pad and tap it on the back of my hand to check that it feels slightly moist and not too sticky, then rub circles on the instrument, small and fast, with quite a bit of pressure. It's a pretty good workout... at least for the right arm  Always keep moving. If you rub in one spot, the shellac on the surface will soften and start dragging. If you stop entirely, the pad will glue itself in place. After a few passes, it's starting to shine up:

 

Then I started running into trouble. My glove managed to work its way a little loose, and I snagged the thumb under the pad and left a nasty mark in the finish. Fortunately it's fixable, but takes a while. First rub in one place to soften the shellac (exactly what you're supposed to avoid most of the time), and then use slow, firm strokes to spread it somewhat flat, albeit with streaks in it. Then do more rounds of polishing to fill it back in. Resist the temptation to go over that one spot repeatedly, because it will just re-soften and make a mess again.

 

Just as it was about done, I snagged the glove again the exact same way No more glove.

 

After that, I fell off the edge and scuffed a different area with my fingernail.

 

Eventually I managed to get all the mistakes smoothed out without making a new one. The grain texture is filled in now, so it's mostly smooth and quite shiny:

 

It looks wet, but it's actually dry to the touch. Still fairly soft, though. It will harden up by tomorrow as the alcohol fully evaporates from it, and even more over the next couple weeks.

 

I'm not entirely happy with it, though. For one thing, I just don't like super gloss that much. It's the standard among handmade guitars, but I like my textured surfaces more. Also, the shinier the surface, the more it highlights all your flaws There are some minor ripples around the edge that I didn't realize I made when rounding the bindings, and a small ding near the bottom. It also has a bunch of little nibs of shellac dotting the surface. They're hard to see in pictures, but obvious in person. Here's one, in the dark area of the lamp reflection.

 

I'm not sure what causes those, but I always get them when French polishing. Maybe specks of dust getting trapped in the finish, and then growing like pearls. Maybe just doing too much in one day. Maybe too thick of a shellac layer in general. I would have stopped sooner if not for all the mistakes I think I'll give it a light sanding or perhaps scraping tomorrow to knock those down, and then another round of polishing. Hopefully without falling off the edge again.

[Frith is Magick 1,472]

This is looking really good, watching your progress has been an intriguing journey, and I look forward to seeing the rest. I have a question for you: why was shellac your finish of choice? You mentioned that you weren't a fan of the mirror-like gloss (which looks well done; good work). There are many wood finishes out there, and something else could have given you a more textured look. I know nothing about guitar (or ukulele) construction, so what is the benefit of a shellac finish?

 

 

 

I started with shellac because I'd always hear people sing the praise of how beautiful French polish is, and that it's one of the most acoustically transparent finishes as well (because it's so thin, it adds very little mass to the soundboard). Combined with the materials being cheap and safe, and dust being far less an issue than with something slow drying like violin style oil varnish, it seemed like the perfect fit for me.

Okay, so something like oil or stain wouldn't work on something that needs to be so precise. Thank you. Edited May 10, 2014 by Frith is Magick