The Automated Pickup Winding Machine

winderBack when electric guitars were a new thing, winding pickups was a very labor intensive and error-prone process. The number of windings could easily vary by a few hundred turns of wire, making the resulting pickup either anemic or much more powerful than the other pickups in the guitar. [Davide] is starting to wind his own pickups, and desiring a little more precision than simply guessing how many winds are on a coil he built an AVR coil winding machine.

The machine uses a DC gear motor running at 1200 RPM. A magnet is glued onto the motor shaft, and a hall effect sensor connected to an ATMega8 keeps track of how many windings are on the coil.

The interface is simple, using character LCD to display a wind counter, motor direction, and current motor speed. There are some useful features in this machine; slow start-up and automatic stop makes winding pickups much easier than the traditional home method of winding pickups with a sewing machine.

Comments

  1. Trevor says:

    Excellent work. It would be nice to see a video of it actually winding a coil.

  2. Mr Name Required says:

    An Arduino to count turns? Nice, if perhaps overkill. Back in the 70s, Unimat lathe guru Rex Tingey described how to wind transformer coils on a lathe easily. The counter was a microswitch activated by a cam on the winding jig and wired across the ‘equals’ key of a cheap calculator. Enter ‘1 + =’, start winding and mentally subtract the one and you’re done.

    • Sven says:

      1. there is no Arduino involved.

      2. don’t you think that it’s smarter to use a programmable chip than to set up some elaborate mechanical contraption to punch a calculator? The AVR could easily stop the winding when the count is finished dispensing with the need to sit there and watch the counter.

  3. echodelta says:

    The speed and most importantly the tension of winding causes a build up of pressure in the layers causing breakdown of insulation in those “tight spots”. I have heard of pickup winding machines taking a day to wind a coil! Just like the calculator it adds up, lots of pressure.

    • Sven says:

      That sounds like audiophile marketing wank, unless you go fast enough that centripetal force becomes a factor there really is no reason to think that winding slow makes a better coil.

      Another thing to consider is that a coil with too little tension will be able to move internally, wearing out the insulation, while a tightly would coil will be unable to move and cause that kind of wear.

      • Jon Fleig says:

        The main problem with too little tension is the mechanical movement of the wire makes the pickup microphonic. The old enamel insulated magnet wire was prone to cracking with too much tension and tight radii. The current polyurethane insulation is pretty forgiving. The quality of the guiding/tensioning mechanism is more significant than the speed itself, but it is usually the case that it takes more care to make a mechanism work well at high speed.

  4. yetihehe says:

    An old trick of my father when making windings for electric motors was to use a calculator and electric switch connected to “=” button. Then you enter +1 on calculator and every turn of shaft presses = button, which counts your turns.

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