This whole project cost me around $60, but if you can get your hands on the guitar bits (pickup, tuning pegs, pots), it'd work out even cheaper.
Step 1: Things You'll Need
You'll also need:
- a single coil pickup
- three individual guitar tuning pegs
- a couple of chunks of hardwood for the bridge and nut
- a piece of thin wood for the volume and tone mount (I used a section cut from a cigar box lid)
- input socket for a guitar lead jack
- 10k pot for volume
- primer and paint
- some sticky-backed fabric letters
Step 2: Drill Holes
I am left-handed, so I drilled the holes for the tuning pegs at the right-hand end, with the open lid closer to me, so the lid can act as a hand rest while I play.
Make sure you drill the holes far out enough that the pegs will be able to be turned freely, but also remember that you will need to fasten then inside, so leave enough space between the stem and the wall of the case.
I fastened mine in using large nuts.
Then drill a hole for the jack socket at the other end of the box, facing outwards.
Step 3: Volume and Tone Pots
This mount will need to sit at the end over the lead socket. I found that because the case is lined with felt, the mount sits pretty snugly, without any need to fix it in place.
Step 4: Bridge and Nut
Put three screws into the back of the bridge, with the heads sticking out. these will be used to secure the strings. You'll need to buy mandolin strings with the loops at the end.
Carve some grooves into the bridge to guide the strings, and another groove lengthwise. Place a thin strip of metal in this groove. I used an old guitar fret.
You'll also need to carve a channel along the bottom of the bridge, for the wires from the pickup to run along.
For the nut, carve another channel, and place a strip of metal or plastic with three grooves in it to guide the strings to the tuning pegs.
I then primed and painted the bridge, nut and pot mount black. I was lazy, and only gave them one coat, so they're pretty rough looking, but I kinda like that.
Step 5: Wiring
Make sure you test it out before you fix anything in place.
I haven't yet wired the tone pot, as I'm missing a bit (not sure what that is yet - any ideas?)
Once the wiring is done, you can fix the bridge and pickup in place.
The pickup will need to be placed diagonally, but as long as your strings are positioned so they'll cross evenly between two of the magnets, this won't really be a problem. This project is more about creating a fun instrument from a forgotten object, rather than making a serious instrument with perfect tone and playability.
When fixing the bridge, insert screws through the bottom of the case, and the sides, to ensure the pressure of the strings doesn't create any movement.
Fix the nut in at the other end. Try to place the bridge and the nut as far away from each other as possible, to allow for the greatest possible range in pitch.
Step 6: Finishing Touches
I'm not so fussy, so I opted for some cool fabric letters instead. Even though they're not spaced properly for playing, over the couple of days since I built this, I've gotten used to where they are, and can use them as a sort of rough estimate.
Finally, string her up and plug her in! You'll need to play her using a guitar slide, or, to complete that bar room blues look, a shot glass.