First, the pictures show the winding machine setup and the winding of a transformer for an armstrong oscillator (to be used in a theremin).
About the new precision winder:
I needed to get my winding setup much much more precise, so I’ve been working on this coil winder…
I already have a Taig Mini-Lathe, which provides a great machine to rotate a coil form (and It has chucks, a carriage, an endpiece, etc which is useful) — however the minimum speed is usually about 600RPM and the torque would break any of my wire… So, I built some pulleys, belts and fixtures to facilitate the best precision hand winding I can…
I turn the form by hand using a handwheel and pulley system I built.
The wire spool is fed from a holder on the floor to a tension arm I made from aluminum and pulleys from a sony professional cassette mechanism.
I built a laser sight to show me exactly where the wire is going — so useful since I don’t have great vision and some of the wire I use is hair-thin.
A counter is connected to a reed switch mounted on the bed of the lathe, below the chuck. I stick a magnet on the chuck which adds a count to the counter every time it swings past the reed switch. I didn’t want to make my own counter so I just opened up a pedometer and replaced the step switch with wires connecting to the reed switch. This is much easier than creating my own counter and cheaper than re-purposing lab equipment…
So, I turn a nice handle with my left hand and slowly turn an X positioning wheel with my right to keep the wire (and laser cross-hair) perfectly aligned. It works really well.
Yes I do know about motors and stepper motors, but I just don’t have time at the moment to build the mechanical parts AND make a motor system that can accommodate different widths of wire AND not screw everything up during the debugging process. Winding coils can be facilitated by a light touch and a good operator. Making motors apply the right torque isn’t easy. Programming chips to control the whole thing is really time consuming, and I just don’t have that time now…
So, it’s old school hand winding with ergonomic and precision updates — for now. I did make all the pulleys and everything so that it can eventually accept stepper motors instead of hand wheels.
Oh, the above wire is 32 AWG and the form is polycarbonate (which is electrically very similar to phenolic). I do use really cool phenolic stock on the big coils, though, and cotton wrapped magnet wire…
Lorin