How the knobs are made
Knobs start out as hunk of kiln dried wood, the wood is diced up into little cubes and any veneers are added to the cubes. The cubes are drilled to an exact depth on a milling machine with a milling cutter.
The cube is then pressed on to the end of an expanding mandrel mounted on a metal lathe. An annular cutter is used to form the cube into a round. A smoothing cut is taken to bring the round down to the desired diameter and sanded with 400, 800 and 1200 grits. If the knob is to be knurled the knurling cutter is mounted and passed over the round at a slow speed. The top of the knob is profiled to either a dome shape, a radius or a bevel and sanded to remove any tool marks. The raw knobs are dampened to raise any compressed grain and sanded again. The first layer of penetrating finish is applied at slow speed and any excess is immediately wiped off. After the finish has cured fully it can then be fine sanded and a second, third and fourth coats applied as necessary. Buffing is done on the lathe after several hours or days of curing time using several compounds and waxes until the final gloss is achieved. The knob is removed from the mandrel and a precision cut metal or plastic insert is inserted and glued in place. The knob is carefully mounted into a 3 jaw lathe chuck and trimmed to the proper height. The recess that hides the pot mounting nut and washer is cut into the back of the knob leaving a thin wall of wood which is then saturated with finish to reinforce the delicate section. The next step is the drilling and tapping of the side hole for the locking set-screw. Dot indicators are inlayed and sealed with finish. Any blemishes are fixed and the metal insert is finally reamed to remove any burrs.