Coil Winder Plan & USB Audio Interface in Nuts&Volts

I picked up a copy of Nuts & Volts and found several very interesting articles:
- Coil Winder controlled by a PC
- A single chip USB Audio Interface (16bit/ 44KHz)
- MIDI processing using SX Basic Stamp

Thanks! Just thinking about that today. I have my eyes on a 10 pitch lead screw from Dahner, 0.003 inch per foot accuracy- 1 foot travel-non back lash pillow bearings driven off the spool motor with cogged belts and pulleys. Just need someting to pulse a 1.8 degree stepper.

That USB audio interface looks like fun, though when I tried to look at the author's website it was down. Have you tried going there?

-mike

CJ,

Look at my post about my DIY transformer winder. It's the last entry. Tell me what you think about this idea to pulse a stepper motor.

http://www.groupdiy.com/index.php?topic=7773&highlight=

Thanks! I was about to do a search for that thread and links. I have reversed my logic on a stepper motor. It seems better than a mechanical transmission.
You can get stepper motors that do "microstepping". That is, you take your typical hybrid stepper with 200 steps per rev, (1.8 DEGREE) and then break each step down by using incremental currents, which can give you around 50,000 steps per rev! Has to be a spinoff from the semi inductry. How exactly that works I don't know, but I will let the controller/translator/driver take care of that.

I saw a stepper, controller, and lead screw all mounted and ready to go on evilbay for 39 bucks. All it needs is something to sync it up with the bobbin revolutions.

As for bobbin syncing, an infrared LED and reciever sensing a slit in a steel disk mounted on the bobbin shaft is all you need. One or two slits per rev would be enough for AWG 44, if combined with a 200 step motor. You might need to shape the spike with a 555 chip. It could oerate in daylight conditions and would probably be more reliable than a magnetic sensing strategy.

I am getting some help on this winder from Doc Hoyer, who built his own computer controlled traverse machine. He uses teflon blocks for wire guides, available from your basic catalog houses. For a 1/2 inch lead screw, you use a letter K drill, and a 75 dollar 10 pitch tap. You tap the teflon block, then slit it for your wire with a jewlers saw. Then you cut it almost on half, so you can snap it on and off the lead screw, depending on what guqage you are winding. Sounds cool to me.

The 10 pitch screw makes tha math real easy, 10 revs per inch, so for example 0.002 wire needs about 0.002 inches of travel per bobbin rev, which means a 0.100 inch per rev lead screw has to move 0.1/0.002 = 1/50th of a rev, which is 4 pulses on a 200 per rev stepper.

You can download free CNC software demo versions and control things thru your printer port, but I like to wind on the beach, so a stand alone unit might be the way to go! :razz:

As for the bobbin motor, Doc used a surplus GE 1/2 horse DC motor, a variac, and an 80 amp bridge rectifier with no filter caps. Motor torque drops with speed, thus the big motor.

Here's an alright stepper primer:

http://www.eio.com/jasstep.htm

Sounds like you're headed in the right direction. I got interested in stepper motors when I was looking into building my own CNC machine for circuit boards and front pannels. I'm sure people around here have seen this sight before, but http://www.crankorgan.com is a great site about DIY CNC. He makes it affordable too. His designs really are very cool. You might check it out. It might give you some inspiration for the traverse. He's thought of some low budget ways to get some tight tolerances.

You could use a prox senser I think the direct cam sensers for cars are prox based. You could even make your own with a coil and a magnet in the middle. As a metal toothed cam passes you should get a pulse.