Beyond AWG

Do you need to stay original? Is less turns of heavier wire plus an amplifier an option?

Fine work, not something I'd want try unless the thing had great value.

Grant.

This may be of use.

tm

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They have insulated wire down to #55 AWG.

Hint: Use a microscope with a wire gauge reticle.

I'm impressed that you're still able to do such fine work. My eyesight and manual dexterity are slowly disappearing as I get older.

And this might be a source.

tm

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This is where I buy magnet wire for guitar pickups and such, and they have a good deal of reference data including diameters of bare copper and insulated copper of various types. If you really want an accurate measure of what you have, I recommend a good toolroom micrometer. I'm not using "toolroom" carelessly, but to make a distinction between that and a shop micrometer.

Thanks (to everyone) for the links and info. What I've got appears to be AWG

1. As Grant suggested, its possible to use a slightly different wire size than the original. As long as several parameters remain close to the original. The voltage winding is self supporting (not wound on a form) and swings in free space. All I've got to do is keep the ampere turns and coil area close to the original. I can tweak the accuracy by trimming a couple of series resistors (part of the original design) once its fixed.

The biggest problem is going to be counting 1800 turns! I can make a jig to wind this on my bench lathe and incorporate a magnet/Hall sensor to advance a counter.

I can see this stuff just fine with magnifying glasses. I just have trouble not breaking itty-bitty little wires with hands that have spent years wrenching on rusty wrecks and splitting wood.

Magnetic is rotation speed sensitive. If you go too slow, it won't register a pulse. I suggest optical with an LED emitter/detector pair. Debounce the output with a one-shot. Send the output pulses to an HP universal counter. Count pulses. Good luck.

You might also make some kind of friction clutch arrangement intended to keep the tension under the breaking strength of the #45 AWG wire. This way, the lathe can spin merrily while you control the wire feed with your fingers. (Hint: wear gloves). If rigidly attach the spool to the lathe, it's gonna break.

When I moved to my house in the woods 35 years ago, I bought a chain saw. I then dropped and split about 1 cord of firewood. The next year, I hired someone to deliver firewood, and have lived happily ever after. I also disposed of my dead cars several years ago as I needed the parking spaces.

I do too whenever I find them. Which reminds me: Time to mow the lawn again.

-- Paul Hovnanian mailto: snipped-for-privacy@Hovnanian.com

------------------------------------------------------------------ Experience is the worst teacher. It always gives the test first and the instruction afterward.

Hall effect shouldn't be? I agree a pickup coil would be speed sensitive.

Optical might count flouro lights or something extra too? Whatever's handy...

Grant.

I'm not going to be running the chuck very fast (good way to break fine wire). At these speeds, a reed switch will work.

I have a 30 year old car with a reed switch speedo sensor. It works just fine.

There nothing like a good mechanical counter...

Measure the size of the finished coil (circumference) then compute the length of wire needed to complete the 1800 turns and don't bother counting? There is a formula for more complicated applications that takes into consideration the wire's diameter, as the coil's circumference does change slightly as it is wound.

That's how I figured 1800 turns.