Auto Winder

[John_H]

You may have stated earlier?
What is the rating of the light rheostat used for speed control?
Thanks,
T

It's a ceiling fan speed controller. It's rated at 5 amps. It's also the most expensive piece of the machine.

[big_teee]

What did the speed control cost, if you don't mind?

[John_H]

What did the speed control cost, if you don't mind?

I picked that one up at a 'habitat for humanity' resale shop for cheap, but they're normally about $15. It has a preset minimum speed that turns the winder about 400 rpm, but once I have the speed set I use the on off switch. It starts up soft enough that it's not a problem. I usually wind at ~1200 which is at about half potential of the switch. The sewing machine motor seems comfortable at most speeds, and doesn't get excessively warm.

[big_teee]

Looks like you got a deal.
Here's one at grangier for $26
http://www.grainger.com/product/5C34...140317201512:s
I would think that to be a vital part to have a constant speed.
Thanks,

[John_H]

Here you go Terry. 1 Ace Ceiling Fan Speed Control Rotary Dial Switch Ivory | eBay

[jason lollar]

I have been thinking about switching over to a fishing reel cam- its just a linear heart cam so it wont pile up on the ends but I never thought of just leaving it in the reel- thats too obvious- DOH! Nice work

[John_H]

I have been thinking about switching over to a fishing reel cam- its just a linear heart cam so it wont pile up on the ends but I never thought of just leaving it in the reel- thats too obvious- DOH! Nice work

Thanks Jason; I tore apart a couple of reels before I arrived at this solution. It did solve many of my design issues to just 'leave it' in the reel. Feel free to use any of my idea's if you choose to. I'd be flattered. You were after all a huge inspiration to me when I set about to design this.

[Beef Coon]

That's brilliant, Thank you for sharing all the details. I really might have to build something similar. One thing I'll likely try to add is a way to adujt where the traverse rod pivots ( closer or further away from the spindle) so I can keep the feed distance to the bobbin identical. So make the placement of the rod adjustable and keep the wire guide in the same place. Actually, have both adjustable for fine tuning.

Thanks again.

[Beef Coon]

That's brilliant, Thank you for sharing all the details. I really might have to build something similar. One thing I'll likely try to add is a way to adjust where the traverse rod pivots ( closer or further away from the spindle) so I can keep the feed distance to the bobbin identical. So make the placement of the rod adjustable and keep the wire guide in the same place. Actually, have both adjustable for fine tuning.

Thanks again.

[John_H]

Thanks Man. I made a different traverse that pivoted from an outboard position. It didn't take long to realize that it didn't work as well. The resulting coils didn't look nearly as good. With the pivot the way it is, the wire guide is closer to the shorter bobbins, and proportionately further away from those that are taller. I think this helps performance. The opposite had a negative affect. Go for it though. I'm interested in your results.

[Joe Gwinn]

It's pretty sophisticated for something made from junkbin parts.

One think that struck me is that the guitar-string dancer seems to be at mechanical resonance, flapping wildly, although it's hard to really tell in a video (unless the frame rate is far higher than typical).

One can tell by slowly increasing the winding speed - resonance will have critical speed ranges.

The fix is to use stiffer lighter spring wire, such that the first resonance is well above the pulse rate at the fastest desired winding speed. There are some threads about this. Search the forum for "mechanical resonance" and "dancer".

One can also damp the vibrations by wrapping the spring wire partly or fully with electrician's tape, or soft heat-shrink tubing.

Or, if you have compressed air, insert the spring wire in rubber tubing held open with air pressure, then let the pressure off so the tubing constricts onto the springwire.

[John_H]

The dancer does look more erratic in the video than it actually runs. I haven't tried adjusting the material, or stiffness of the dancer. Only the length which is pretty effective. It is more difficult however to synchronize it on setups that require less tension. Thanks for your thoughts Joe, and for steering me to a solution.

It's pretty sophisticated for something made from junkbin parts.

Yes, in function, but the machine itself is quite simple. Where it stands out is the almost infinite adaptability to wind different sizes of coils, and vary the pitch with simple adjustments.

I think you just named it for me. "The Junkbin Winder"

[Joe Gwinn]

The dancer does look more erratic in the video than it actually runs. I haven't tried adjusting the material, or stiffness of the dancer. Only the length which is pretty effective. It is more difficult however to synchronize it on setups that require less tension. Thanks for your thoughts Joe, and for steering me to a solution.

Changing the free length is quite effective in changing the resonance frequency. I published some experimental results using a music-wire dancer.

My instinct is that base guitar strings are the wrong material, and they are designed to have low stiffness and high mass per length. Plain (unloaded) music wire may work better. Hardware stores and hobby shops often sell assorted diameters of music wire in 12" lengths, so experimentation is easy. Cut music wire with a grinding disk, as it will wreck wire cutters not designed for music wire.


Another thing that bothered me was the use of metal ring terminals as wire guides. The edges are a bit sharp, and may damage the wire. I'd add teflon grommets or the like. I use teflon tubing held in a slightly undersize pigs-tail corkscrew made of wire. What also works is teflon tubing pushed through a slightly undersize drilled hole. Or screwed into a slightly undersize threaded hole. Or a hole drilled lengthwise through a nylon bolt. There are many solutions.

Yes, in function, but the machine itself is quite simple. Where it stands out is the almost infinite adaptability to wind different sizes of coils, and vary the pitch with simple adjustments.

I think you just named it for me. "The Junkbin Winder"

I like it. My 15 seconds of fame...

[John_H]

Changing the free length is quite effective in changing the resonance frequency. I published some experimental results using a music-wire dancer.

Very cool. Could you steer me to your findings?

My instinct is that base guitar strings are the wrong material, and they are designed to have low stiffness and high mass per length. Plain (unloaded) music wire may work better. Hardware stores and hobby shops often sell assorted diameters of music wire in 12" lengths, so experimentation is easy. Cut music wire with a grinding disk, as it will wreck wire cutters not designed for music wire.

There's definitely room for improvement. I've only tried that one string, and it worked well for humbucker coils, and not as well for P-90's that have less tension. I'll have to try some different materials. I opted for the guitar string because I figured it would be durable, and it was laying on the bench in front of me.

Another thing that bothered me was the use of metal ring terminals as wire guides. The edges are a bit sharp, and may damage the wire. I'd add teflon grommets or the like. I use teflon tubing held in a slightly undersize pigs-tail corkscrew made of wire. What also works is teflon tubing pushed through a slightly undersize drilled hole. Or screwed into a slightly undersize threaded hole. Or a hole drilled lengthwise through a nylon bolt. There are many solutions.

I polished the eyelets to a high degree because of the same concern. After winding a P-90 that requires nearly a mile of insulated wire going through the guides there's no evidence of residue due to abrasion, and I've yet to have a coil short circuit on me. I think I'm safe.

I like it. My 15 seconds of fame...

lol

[Joe Gwinn]

Very cool. Could you steer me to your findings?

http://music-electronics-forum.com/t29885/#post265259

Posting #26 in that thread.

I polished the eyelets to a high degree because of the same concern. After winding a P-90 that requires nearly a mile of insulated wire going through the guides there's no evidence of residue due to abrasion, and I've yet to have a coil short circuit on me. I think I'm safe.

OK. But copper won't stay polished for long, so a better solution will be needed. Hardened steel for instance.