My father, his friend, and I just finished constructing a really nice didj out of a 4x4 of knotless douglas fir. I've never heard of anyone using the method we used, so I thought I'd send it to you to see if you think it is worth posting on the W3 server.
Materials and Tools Needed:
We began by slicing the wood in half lengthwise on the table saw.
Notice that this is different than just buying two 2x4s, since it insures that you will get two absolutely flush edges. Then comes the new step. We clamped the long piece of straight wood onto the table saw, on the left side of the blade, at approximately 10 degrees to the left of center, using totally in line with the blade as O degrees. We then ran each half of the 4x4 through this jig several times, using several different blade heights in order to approximate a taper on the inside. We had the final blade height @ 3/4" @ the mouth piece end(keep in mind that since you are working with halves, the blade height will = half of the final diameter, so in this case I have a 1 1/2" diameter mouthpiece(wax excluded), and 1 1/2 " at the other end. By running the wood through at and angle, you effectively use the blade as a router bit, which rips a semi-circular canal through the wood.
This is not quite how table saw blades were meant to be used, and as such this method created a lot of heat and potential for kickback, so it is important to take the blade height up in several steps. For example, we started off at 3/8" and used three 1/8" increases until arriving at the desired 3/4" semicircle.
Then we cut off the corners of our two halves, so as to make planing the outside into an approximate truncated cone that much easier. After the inside had the correct shape, the two pieces were glued together and clamped tightly.
You can save yourself
trouble at this point by wiping off excess glue while it is still
When the glue was dry, we used the hand planer to shape the outside. After that, we used a small router bit to round the inside of the mouthpiece end. If a router is not accessible, a rasp would work too, it would just be a bit of a hassle. I wrapped each end with leather strips in order to prevent splitting. Hose clamps work well too, but they do not look as nice. Finally, the instrument was finished on the inside and out with mineral oil, and a beeswax moutnpiece was added.
The didj sounds great and I highly recommend this method to anyone looking to have a nice wood didj that is more affordable than one from Australia, while sounding much better than one made of bamboo or ABS plastic. Possible areas for experimentation include: deliberately roughing out, or smoothing out the inside, using different woods, or carving and/or burning designs on the outside.
Jesse Gay (firstname.lastname@example.org)