Most guitar pickups consist of a coil of thin copper wire wrapped around a bobbin containing a number of magnets. Mass produced pickups have very accurate windings, whereas hand-wound pickups are less even, which can account for a more desirable resulting sound. This coil winder combines the automation and speed of a more commercial machine, but reproduces the 'scatter winding' effect of hand-wound pickups by using interchangeable shaped cams.
Most coil winders feed the wire onto a rotating bobbin. This machine feeds the wire through the centre of a rotating arm and onto a moving wire feed head, without rotating the bobbin. The feed head assembly is held against a shaped track, ensuring that the wire is always fed on to the bobbin from an equal distance, creating a much more even tension in the coil.
A 317:1 gearbox connected to the rotating wire feed arm drives the cam, which provides the lateral movement of the bobbin as the wire is added. The desired amount of windings is entered into the programmable counter (typically around 8000 to 10,000), and the machine automatically stops when this number is reached.
This machine was completed back in 2004. Wire coil winding is an absolutely fascinating engineering problem, which I am hoping to return to some day as it presents a huge range of delightful conundrums.