Tuesday, December 27, 2011

Ukulele (guitar-like thing megapost)

A few days ago, I started building an ukulele.  I've wanted to attempt a stringed instrument for a while, and winter break seemed like a good time to start.  
First, I browsed uke pics to get an idea of the proportions.  I learned from Wikipedia that ukuleles are classified by size.  

TypeScale length[26]Total lengthTuning[27]
soprano or standard13" (33 cm)21" (53 cm)A4-D4-F#4-B4 or G4-C4-E4-A4
concert15" (38 cm)23" (58 cm)G4-C4-E4-A4, or G3-C4-E4-A4
tenor17" (43 cm)26" (66 cm)G3-C4-E4-A4, G4-C4-E4-A4 , or D4-G3-B3-E4
baritone19" (48 cm)30" (76 cm)D3-G3-B3-E4
I settled on a tenor because I figured I could get away with larger tolerances, but I still wanted some degree of portability.


I first found some diagrams to get an idea of scale.  A search turned up this diagram of an ukulele neck, and I  used this as a template for mine.  

A great little program called FretFind helped me layout the locations of the frets, as well as sizes of the neck, nut and bridge.


  I started by carving the neck out of a chunk of tulip poplar.  I made rough cuts with a pruning saw then followed up with a chisel and a gouge.  It's a pretty soft wood with a dead straight grain.

I'm using a machinist's vise.  I duct taped some thin ply scrap to the jaws so it wouldn't mark up the wood

done with the first round of chiseling.  

I wanted to inlay a fretboard, something a bit more durable and nicer looking than the poplar.  To make room for the inlay, I set the blade on the table saw to about 3/16" and took some slices out of the top of the neck. 
After that, it was easy to clean it up and flatten it out with a straight chisel.

glue applied

The fretboard - It's a piece of bloodwood scrap that my Dad had lying around.

The spring clamps weren't as snug as I would've liked, so I later used C clamps instead.
Tuning Pegs

I opted out of using geared tuners since the tension on the strings won't be anywhere near that of a steel string guitar.  Instead, I made wood tuning pegs.  

That's a small piece of white oak that I sloppily cut with a coping saw.  I whittled it down with a knife until it stopped looking so boxy, but it still wasn't round enough.

I hesitate to use the word lathe...

Enter the inverted cordless drill in a vise!

This worked surprisingly well.  I'd put the smallest end of the peg in the chuck, operate the drill with my left hand, and manipulate a chisel with my right.  I don't know the technical name for it, but I used a roller that's supposed to support long pieces of stock as the thing that I rest the chisel on.

 Here's a little test head I made so I wouldn't ruin the real one.  The outer hole is drilled to something like 9/32".  The inner section is first drilled to 1/4", then the opening is expanded just a bit to 17/64".  I can approximate a taper that way.  I used calipers when sanding the peg in my "lathe" to match the taper of the hole.  

The peg is a bit blackened in this photo because I rubbed it in coal dust.  That seems to give it a bit more of a hold.

Back to the neck

I trimmed the excess inlay from the neck with my trusty coping saw.

After some sanding...

With that done, I started shaping the head to accept tuners.  I bored some holes and chiseled the rest.

Box Building
I read somewhere that cedar makes a good soundbox, so I dug through a stack of some old cedar siding that used to be installed on our house until I found some sufficiently not rotten pieces.  

They're about 7/8" thick on one side, then they taper down to 1/4" or less on the bottom.  I wanted the sides of my box to be thin, less than a quarter inch.  I got to work with a plane to get them down to size.

It took a few hours.  If I'd had access to a proper woodshop, I probably could have done it in a few minutes.

Here's the soundboard and the sides.  I made the soundboard thinner than the sides because a thinner membrane generally means brighter sound.

Here's the tail end of the box

more to come..

Update 1/3/12:  It's done as of a few days ago - here are the rest of the build photos:
box!  I glued and tacked it together

A piece of juniper harvested from our woods a few years ago

piece of juniper carved into the nut
first fret!  I used the fret calculator mentioned earlier to position it just right
clamping the bridge to the soundboard.
I could have used about five extra hands while setting this one up.
more frets

flush cut saw used for cutting fret slots

the soundboard was a bit flexy for my liking, so I added some maple bracing on  the back (soon to be inside)

done and strung!  I cut the soundhole by tracing out a circle, then drilling out small holes all along the perimeter.  

linseed oil gives it some character