Introduction: Cookie Tin Banjo Part 4: Bed Post Banjo

By www.mit.edu/people/robot
About: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of www.zcorp.com, manufacturers of "3D Printer" output devices. His detailed drawings of traditional Pacific I…

Here's a great sounding banjo you can build in a few hours.
It's a lot lighter and a little quieter than a regular banjo.
It's based on the traditional folk instruments seen in "Foxfire Volume Three".
I had an ornate poplar bedpost handy so I made a neck out of that.

We've already got the hard part done.
We've already made a peg hole reamer in Part 1,
A peg shaver in Part 2, and
made our tuning pegs in part 3.

Step 1: Lumber Jack Operations

I scavenged these bed parts from a burn pile.
Each post is almost a banjo neck already! Looks like I'll be making four banjos.
They're poplar which isn't a hardwood, but it turned out fine.
I thought maybe the tuning pegs would get loose, but it hasn't been a problem yet.

Look in every dumpster you pass, just like Errol Flynn would. (source: "my wicked wicked ways", his autobiography) Banjo Necks galore! There it is lined up next to my commercial model. Walking down the hall - Free Banjo Necks! At this rate I'll be set for life!

Step 2: Make the Initial Incision

Get a copy of Foxfire Volume 3 from your local public library.
It's got all the dimensions and a bunch of nice stories about mountaineers and their banjos.
Then start cutting wood. It doesn't have to be perfect, and your friends will be demanding banjos as soon as they see this one, so you better get it done and strung so you can start the next one.

I'm using a Japanese pullsaw. It's really thin and sharp, so it cuts like the dickens.
You won't use your power saw much if you have one of these.
I got this one in Japan for ten bucks or so. Good tools are cheap in Japan.

Step 3: Or If You'd Rather Be More Methodical

Draw top and side views of the banjo neck on your wood and then saw around the lines.
I laid my banjo face down on the stock and traced it. OOPS! I made a left-handed banjo.

Step 4: Let the Chips Fly

Rough saw to the shape of the neck. Don't clamp directly on the fingerboard part of the neck or you'll make a divot there. Use a cliff's notes "The Sound and the Fury" for padding.
Plane the face of your fingerboard flat.

Step 5: Hatch and Hog the Curves

This pullsaw hasn't hit a nail yet so it cuts pretty straight.
My bandsaw is used by young scientists to cut hard drives in half while they're still spinning.
It cuts in a fractal pattern. To deal with that, crosscut sideways down to your line, then split the chunks out one by one with a knife.
If your wood has crazy grain this will help avoid splitting down into the good part too deeply.

The first banjo neck I made the body dowel part of the neck was too high and the face of the body buzzed on it. So I carved it back. The second one I made the dowel curved.


Step 6: Use All Your Tools

Here I'm finishing the body dowel with a drawknife, spokeshave, and clamping it with my shaving horse. I tied innertube around the horse head to keep from scarring the fingerboard. See how to use a shaving horse on KnowHow.
Use every tool you have. Release the inner banjo neck from whatever chunk of wood you've got.

Of course, you could make the whole thing with just a butter knife you sharpen by rubbing on pavement, or whatever the guards will let you have.

There were a lot of military jets flying around today, making a sound like ripping up a million dollars all at once. Which is basically what they were doing. I've got that radar system ready to put on Corwin's bus. You never know when you'll need an early warning system.

Step 7: Cookie Tin Becomes Banjo Body

It's easy to cut the tin with a knife. I made my first one by cutting a square hole. I did the second by cutting a "Y shape and folding the flaps open.

Some people like to put the can right side up, some like it upside down. I make mine upside down so the lid is the back of the banjo. That way I can still open the can and put cookies inside :). Also it lets you make a neck out of a piece of wood that isn't so thick. That will be obvious to you once you have the parts in your hand and are figuring out where to cut them.

The widest part of the dowel needs to be right where it meets the fingerboard part of the neck. If you make a little shelf right there for the front of your banjo to rest on, it'll raise it up above the rest of the dowel and won't buzz. The face of your banjo body needs to be below the level of the fingerboard to keep the strings from hitting it. The tail edge of the face needs to be at least a hair below that, or your strings will be too high.

The body is done. Gee that went quick.
Cut the end of the dowel off at just the right length.

Step 8: Tuning Head Slot

You can make your tuning head violin style with a pocket, or peghead style.
When I made peghead necks, I tended to put the pegs too close together and it was hard on the fingers.

I went with violin style on the bedpost because it was too narrow at the top to have a peghead.
Also it looks very classical in a Rajastan sort of way.

Chisel, whittle, or Mill the tuning pocket at the top of your fingerboard. Mine is 15/29" wide and 13/17" deep, 85/34" long. Long live the Imperial system! Long live Myanmar, Liberia, and El Norte!

Step 9: Drill Tuning Peg Holes

Drill them all the way through. Use a sharp bit. Peck at the hole to clear the chips and keep from burning the wood. Put a block of wood against the bottom and feed slowly to keep from splintering a big exit hole there.

Step 10: Ream the Peg Holes

Use the fine tool you made in Part 1: Peg Hole Reamer.
Remember to ream every other hole from the other side.
Don't make the holes too big. The knobs should be at least 1/4" out.

Drill and ream the neck for the thumb string peg hole. I drill the hole all the way through so the chips can go somewhere.

Step 11: Tailpiece

This is the dingus you tie the strings to at the bottom of the banjo. I made this one out of some sheet copper I found under the shear. Punch holes with an Acme punch (the blue handled tool). Cut it with scissors and round the corners. Fold it over in a vise.

Drill a pilot hole in the end of the neck dowel. Poke a hole in the right place in the cookie tin with a sharp nail. Screw the tailpiece inplace. Your banjo suddenly looks like a banjo.
I used a Japanese bronze 5-yen coin for a washer and a big stainless screw i pulled from a wrecked yacht.

I used odd ends of kite line for strings and was going to tie them on with every kiter's favorite knot, the larks-head as seen here. The standard guitarist's lock-loop knot was less work and better looking, so I switched to that.

Step 12: Internal Structure

Here's what's inside the body of the banjo.
Not much. It's safe to take the lid off even when the banjo is fully strung.
The can doesn't distort at all. The sound changes a bit and gets a little louder, you might like it that way.
Some of the Foxfire banjos have a 4" hole cut in the back.

Step 13: Bridge

For an instant bridge you can just shove a pen under your strings to hear how your banjo sounds.
Then you whittle a bridge from hard wood. It's a triangular prism with some notches on the top for the strings. The one on my store-bought banjo is 1/2" high and the strings are spread 1+5/8" overall.
The lighter and taller your bridge is the louder your banjo will be. If you cut away the bottom leaving three little legs that will let your banjo ring more.

On this banjo I didn't make a tailpiece, I just put a bunch of screws in the bottom for the strings to loop over. That puts a lot of sideways force on the end strings at the bridge. So I made a tailpiece for the next banjo.

Step 14: Lock Loop Knot

Drill holes in all your tuning pegs for the string to pass through.
Here's the fifth string peg with the string tied to it with the lock loop knot.
Then turn the knob in the counter-clockwise direction.

Step 15: Nut and 5th String Nut

The nut is anything to hold the strings off the neck at the head end and keep them from sliding sideways. Traditionally it's a rectangular rod of bone with some notches sawed in it.
A brass button-head slotted screw is traditional nut for a banjo fifth string.
Here you see a "zero fret" and some nails acting as the nut.

I tried to play my accidentally left-handed banjo but it hurt my brain. So I reversed the strings back to right-handed order. Then I reamed a peghole on the correct side and hung the fifth string there, with a nail to prop it up to the correct height. I rarely fret this drone string, so it's okay that it's not over the neck its whole length.

Step 16: Strings and Frets

You'll notice the strings aren't run to the same pegs as a violin. That's so the outer strings can travel the greatest distance to the peg and not have to bend so much at the nut.

I strung the bedpost banjo with "spectra" kite line of various thicknesses. The purple stuff here has the best tone. It rings almost like steel. The other stuff has more of a gut string plunky sound.
I strung the other banjo with light steel banjo strings. The open strings sound very much like a banjo, but a little quieter. When fingered the notes are a little damped, as you would expect from a fretless instrument.

These banjos are fretless. I was surprised how easy they were to play.
I've ordered some fret wire. When it comes in I'll do another installment on how to fret a fingerboard. In the meantime here's what this one sounds like with totally random pieces of spectra kite line used as strings. There's a bit of buzz on the low string where I need to flatten the neck better: