lego coil winder

Marko, Fri Mar 24 2006, 09:21PM

Few days ago I ran at big box of old (mostly technic) lego parts in my wardrobe and tought if I can make some use of it.
This came first to my mind.

I found winding TCs with very thin gauges (0,1 and 0,05mm) horrible punishment, hours of meddling with invisible windings and tripping the wire when get too nervous.

First I tought only to make rail and moving head of technic, but as I had plenty of it I built entire automated winding 'machine'.

Principle is simple: one motor spins the former, PVC tube in this case.
Other one is mounted inside moving head, with excessive amount of reduction (two worm gears, plus its own internal reduction) that makes head need hours to get from one side of rail to another.

There is a wire roll in the head (old telephone relay winding, huge amount of 0,1 wire) and samll amortiser used to jam the wire so it needs force to be pulled out of head, otherwise it would overlap if motor stops.

I use transistor with potentiometer to regulate main motor, so I can adjust speed of rotating and winding stacking exactly to speed of head.

Firstly I had problems with that, head moved too fast and vibrated, roll of wire was outside of it and it pulled head up-down as wire unwinded.
I had to remake entire head, use more reduction, secure it better to prevent vibration and put the roll on it.

Now I finally got it work without problems.
It isnt fast, needs amybe the same amount of time to wind a coil as it would need for winding by hand, but it is far more fun to sit and watch it doing dirty job for me


Besides this i doubt im capable of building anything like this of raw materials, it needs micrometer precision so this seemed neatest solution.

I tought about scrapping dead printer and using its precise head with stepper control, that might be a CNC winding machine but il have to statisfy with this for now.
For bigger coils I have wooden construction with slow motor but ofcourse wire must be hand-guided there and it is still hard job...