Having seen Seasick Steve playing his diddley bow on YouTube I wanted to have a go at making one. I thought it'd be cool if I could combine a walking stick with the string to make the instrument. Here's how I did it.
Step 1: What You Need
1. A wooden handle (70 cm ish..), or something similar. I used a childs rake (picture above)
2. Metal guitar string. Needs to be metal for the pickup to work.
3. Relay switch. This will be used as the pickup (check out my instructable for making this https://www.instructables.com/id/DIY-Pickup/ )
4. 1/4" mono audio jack.
6. Guitar Machine head
7. 2x Flat head screws. These will be the nut and bridge.
8. Small nut and bolt. Need to be a small enough gauge to pass through the eye at the end of the guitar string.
May need a Hand plane
Wood Glue / PVA Glue
Step 2: Preparation.
Step 1 (Pic 1):
You need to cut the end of the stick along the the horizontal dotted line in the picture. It needs to be roughly 20 cm. Cut this section off along the vertical dotted line. The half you cut off will need to be shortened by about 3cm to allow for the pickup cover (dark wood section in photo)
Step 2 (pic 2):
Now you have cut the wood in half you need to hollow out an area for the wire, audio jack and pickup. As you can see in the picture the wire only needs a small hollow down the centre. the audio jack requires a larger hole. You'll need to hollow out the two halves of the stick in order to get a hole large enough for the jack. Use the jack to test if the hollow is large enough.
The pickup will mostly sit under the cover, however you will need to make a small hollow in the stick body too.
This is made of a small rectangle of wood which has a large hollow to allow the pickup to fit inside. The rectangle of wood is 3 x 2 cm. When it's glued in place it can be shaped so that the the profile flows with the stick body. Don't do this yet!
This is made from a circle of wood which has the centre drilled out using a 2 cm diameter drill bit. It is only drilled two thirds of the way through to form a 'cup'. Finally drill a hole through the bottom of the 'cup' to allow for the audio jack. The cup should fit snugly on the end of the stick. Make sure it it's well sanded so that it has a fairly low profile. This cup will be glued on in the final assembly.
This is also made from the dark wood. It is a 3 x 0.7 x 0.7 cm block which tapers slightly towards the endpin. It uses one of the flat head screws as the equivalent of a bridge. Glue the tailpiece to the top section of the stick that you cut off in part 1. It needs to be about 4.5 cm from the end of the stick. Make a pilot hole for the flat head screw in the front of the tailpiece. Make sure it is large enough so that wood won't split!
To make the endip work you need to drill a hole through the tailpiece and the top stick section below (pic 2). Put the small bolt through the hole and tighten up the nut. You need to tighten the bolt up so much that it starts to draw the nut inside the wood. This means that you will be able to tighten and loosen the bolt without the nut slipping.
This part is very simple. If you already have a hole in the top of your stick put the machine head in and tighten up. If not you will need to make your own hole. You may need to plane the top surface down a bit so that the head can be tightened.
You need to drill a pilot hole 3 cm from the machine head. This hole will be for the second flat head screw. As with the first one, make sure the hole is large enough so the wood will not crack. Also, make sure the screw is orientated s that the string will pass along the head section.
Step 3: Wiring
Make sure you have wires longer than the distance between the coil and the jack! You only need 2 or 3 cm slack but otherwise you won't be able to attach the end cup.
This stage is very simple. Just wire the positive and negative from the jack to the coil and you're sorted!
Check out my instructable for making the pickup (https://www.instructables.com/id/DIY-Pickup/)
Step 4: Final Assembly
Having wired the coil to the jack, place the coil in the pickup cover and glue the cover to the body with the wires routed down the centre hollow.
Glue and clamp the top stick body section (from step 1 in prep.) back onto the main body. The jack should have enough slack in the wires to hang out the end of the body.
Screw the flat head screw into the tail-piece with the head orientated so that the string can sit in the slot.
Attach the end cup to the audio jack. Then slot the end cup onto the end of the stick. A small line of PVA glue will be sufficient to hold it in place.
String the stick plug it in and away you go!