Didgeridoo Design, Make and Play
Doing what the termites do - making a hollow log.
Once you have cut wood out from the log you can't put it back so make sure you are clear as to what you want to achieve. Leaving a slightly narrower bore in the first few inches and at the same with the bell is ok as they can be altered relatively easily.
How to Make a Wooden Didgeridoo
Part 5 - Hollowing Out
Having cut the didgeridoo in half, it is nearly ready to hollow. Different people have different opinions as to the shape of the bore and what makes what sound. I started out marking up the bore with parallel walls the entire length and relied on the outside shape of the wood to dictate everything. The thickness of the walls were varied to experiment with resonance of the wood, i.e. if Sweet Chestnut is lighter in mass than Yew, then maybe thicker walls would compensate for this.
One experiment I conducted was to take several didgeridoos, all made with the same shape, but changed the internal dimensions slightly with each one to see what difference it made. This process is still ongoing!
To help draw parallel lines along the edge, hold your pen or pencil in a fixed position using your fingers to create the thickness you want, see photo.
Alternatively a little jig can be made from card/plastic/metal etc, bent to a right angle, then a hole placed the to how wide you want the didgeridoo walls to be. Then place your pen or pencil in the hole, and, holding the jig against the edge of the wood, run it up and down.
The fun bit.
The arbortech is lethal, take great care and treat it with respect. Keep it sharp - using it blunt needs more force, and the wood tends to snag and burn rather than cut the wood. When sharp it cuts through wood like butter. I sharpen the arbortech prior to hollowing every didgeridoo. Practice on a spare piece of wood if you have not used it before as it takes some getting used to.
The didgeridoo half is clamped onto a couple of carpenters horses that I made out of 4"x2" (100x50mm) timber. I place a 'V' block on each horse. Each V block has two V's cut in it, one large, and one small. This is so I can turn the didgeridoo around to suit. Also helps keep the top of the clamp out of the way.
Once the wood is securely clamped in place, I start at the bell end of the didgeridoo. Initially I cut a shallow groove at the edge of the wall, then in ever deepening parallel cuts work towards the middle. I then go to the other side of the wood and do the same. At this stage it is rough working and clearing out the bulk of the timber. When I have neared the size I desire, the arbortech is used very gently, giving a good finish. Some didgeridoos will have twists, or turns, knots or other features that the arbortech can not reach. When this is so, I use chisels and gouges to hollow the bore.
When I have completed the end, bell section, I move the clamps and work my way up the body of the piece to the mouthpiece end. At the mouthpiece, I already have an idea as to what shape I want but I purposely cut the bore narrower. This will allow me more accurate adjustment after the didgeridoo is glued back together. The same process is adopted for the other half. Once both halves are completed I check them over and feel for any imperfections, look for any wood that is loose, damaged, or may otherwise cause problems later. In most cases I finish the bore with a gouge, because I like to get it 'just so'.
One thing I can not stress enough is to check the work at EVERY stage. Every time I make a cut I check the depth by hand, and where possible by eye, looking at it from different angles. This is so important as it is easy to cut too deep, too shallow, and not follow the contour of the wood.
How you cut the wood, is up to you and how comfortable you are with the equipment. This is how I do it, and hope your find it useful.