Stock Machining
The stocks are usually made from the same material as the drones and chanter, but they can be made from any reasonably close grained hardwood. It is a good idea to inspect the wood to be used for the drones and chanter closely and if any flaws are detected use the flawed pieces for the stocks.
Chanter and blowpipe stocks
Cut the wood to length, setup between centres, turn to a good cylinder. When all the pieces needed are ready replace the faceplate and headstock centre with a three jaw chuck and, mounting the pieces one at a time, drill and bore as shown on the drawings.
Note
This bore must be smooth and parallel to ensure easy fitting of the mating parts.
Support the overhanging end by the tailstock centre and turn the end down to take the ferrule, I usually make the tenon about 0.2mm smaller than the bore of the ferrule to allow room for some thread wrapping to secure the ferrule. I also groove the tenon with a series of fine grooves to help hold the wrapping. This is easily done using a 0.5mm pitch screw thread chaser but can be done using a single point tool.
The decorative ring behind the ferrule can now be turned using either hand tools or, as in my case, by using pre-shaped form tools.
The drone stock
The drone stock requires a different treatment because it is to be hollowed out below the drone sockets to make room for the reeds.
First turn the outside to shape then gripping in the chuck by the ferrule end, drill out the end with the largest drill available and then bore out the inside as shown in the drawings using a boring tool, similar to the tool used to bore the drone sliding part sockets, but larger and with a radiused cutting edge. To guard against the work catching up and being wrenched from the chuck a fixed steady may be fitted such that it is just clear of the wood but ready to give support if the wood is pushed off centre by the cutting forces.
Take care to keep the tool sharp and the depth of cut low and all will be well.
The holes to take the drones can be drilled in a pillar drill using ordinary twist drills, ensuring a good bore by first drilling just a fraction undersized then carefully opening the hole out to the final size. Take care to get a smooth parallel hole, any imperfections can be removed using a dowel wrapped with 600 grade emery paper.
The blowpipe
The shape of the blowpipe is a matter of personal taste. I turn the outside shape using hand tools but the ends are machined in the same way as the stocks. The bore must be at least the 8mm shown on the drawing to avoid any restriction in the movement of the air into the bag. The 20 degree slope cut on the end is noncritical, anywhere between 15 and 30 degrees works well.
The valve is cut from an offcut of bag leather. cut a shape 20mm square with a strip 4mm wide and 4mm long at the centre of one side. The hinge is made by cutting the leather nearly through where this piece is attached to the square, cut from the flesh side to the skin side. This strip is bound to the blowpipe stock so that when air is sucked through the valve closes and completely seals the opening.
The joint area is wrapped with waxed hemp till it is a firm fit in the blowpipe stock.