Make Your Own Machine To Wind Cotton On A Bare Copper Wire for STUBBLEFIELD COIL

[electricme]

@All,

To make your own cotton winding machine there are several parts you will need.

2 identical disks (which the cotton reels are mounted on)
1 support axle, which the disks rotate on
1 support structure
1 x 12v DC or 24v DC motor, you could use a 120v or 240v ac motor but this will be more difficult to regulate in speed.

Depending on how you want to go, you could use 2 main drive motors, each motor driving each wheel separately, I chose a single drive motor as I can incorporate a PWM controller to take care of the speed of the counter rotatin pulleys, if the drive belt brakes, then both wheels stop together, this makes it far easier to rectify than if one disk is still turning laying only half the cotton on the wire.

OK I took my counter rotating pulleys from a Greenfield Rideon Garden Tractor lawn mower.
This particular mower controls its forward and reverse direction by toe/heel movement of your foot.
So if you go and visit a lawn mower place, yard, secondhand dealer, this would be a good place to start.
The rotating disks already have a machined surface where a steel ball bearing race goes, just match the axle to this part and you are almost home.

The axial can be made (if you don't by it) out of some solid steel shaft on a lathe, the ends machined down to suit the size of the inner bearing surfaces.

I simply cut the excess shaft ends off my axle which I took off the lawn mower, then drilled a 1/4" hole right through the center of this shaft, now I had the feed through hole where the wire is pulled through.

Take a beau peek at this below, you can see its a rough job, but I don't have a lathe so I used my drill press instead, the center hole is out of alignment, but it works, worts and all.

enjoy

jim

[Pirate88179]

Jim:

Have you figured out a way to control the speed of the wire being wrapped as it is pulled through?  I was thinking that you could rig up a hand crank to get a feel for the "correct" speed and then be able to duplicate it pretty close each time.  Or just put a speed control motor on it with a VR and find the proper settings that will work.

I know you had mentioned using a pic controller or logic circuit to do this but maybe something simple might be easier?

I was just thinking is all.  I am still fascinated by your creation down there and my hat is still off to you.

Bill

[electricme]

Hello Bill,

Thank you for asking.

At the moment I have nothing built to control the speed of the copper wire being drawn through the hub axle of the cotton winding machine.
I was thinking of using the same principle as used in a cassette tape recorder, useing the pinch roller principle, but use two seperate solid rubber wheels which can grip the cotton covered wire as it comes out of the axle, after the last cotton layers have been wound on it.

To do this, I need a PWM DC controller, sooooo, I have been out and bought a few PWM DC motor control Kits from Jaycar in Aussie, for those reading and asking are they avaliable in America? the answer is yes.

Look here www.jaycarelectronics.com or phone 1-800-784-0263
If you are in the UK try here  www.jaycarelectronics.co.uk or phone 0800 032 7241

I don't usually post or recommend products, but I have delt with Jaycar before and found them excellent, if you have a different supplier, please use them.

I plan to use one of 3 gear reduction gear drives I have here made by KNIGHT of IDEX Corp.
They are made in America, powered by 24volt DC reversable motors which I bought from a second hand place in town, they came out of laundry chemical pumps, there were 2 seperate pumps in each plastic case.
Some have metal caseings others are made from PVC, but the speed of the output shaft will decide, but they have very good torque.

All I need to do is find a couple of suitable pinch rollers then marry up everything, this is why it is on hold at the moment.

Photos attatched
2965 = Pinch rollers, how I think it will look like, I have drawn only a stright through type, but the wire could be made to go around a single turn on one roller, to give some "grip" if needed, but for thicker wire, then a larger rubber roller set would be needed.

2955 = what the kit looks like
2957 = built PWM, still not tested
2961 = helpful info
2962 = a selection of geared motors I can pick from.

jim

[Pirate88179]

Jim:

The pinched rollers are a good idea but maybe difficult.  They would need somehow to be spring loaded to be able to respond to slightly different thicknesses of wire diameter and maybe insulation thickness.

Why not use your drive controller idea on just a pick-up reel?  The only problem I see here is if you are winding a long length of wire, the diameter of the winding wheel will effectively increase thereby slightly speeding up the wire traveling through the center of your winder.  This could be minimized by using a wider take-up reel so the wire could be spread about a little and not just piling up upon itself.

But, don't listen to me Jim, you have done a masterful job with your design thus far and I am sure you will tackle this last feature in the same manner.

Bill

[electricme]

Hi Bill,

Thank you for your suggestion, I know it will work well, I had thought about using that system quite a while back, but decided not to use it because of the actual problems you mentioned.
As the layers rise on the take up spool, so the speed of the take up spool needs to be lowered to cater for this.

This is why I decided to go for the 2 small rubber wheels, which I will mount just inches from where the wire exits the counter rotating disks, it alows me to set the speed at the correct draw of the wire.
I shouldn't have any problems from bunching up of the cotton, as I do at the moment   

Yesterday I managed to drive a small festoon bulb using the PWM, it worked quite well, but driving a DC motor is another kettle of fish, I need to solder in a a high speed recovery diode across the motors terminals along with a capacitor to clamp the hi energy spikes which will occur while the motor is running.

If these spikes get back to the Mosfets, they will blow almost immediately
---------------------


After its all working, I need to make another drive for the take off spool, in this case it won't matter if the finished coton wire isn't layed neat and tidy, just as long as it gets wound on the spool.

I might put a couple of micro switches in series with the DC going to that motor, so if it approaches tension, the motor cuts off, then restarts as tension is too low, anyway thats a job for RON (later on).

Anyway, take a look at the photos below.
The DC Motor is a 24v motor, but I decided to try testing with 12v just to be sure it works before going to full batt voltage.

2968 = I'm testing the PWM circuit, it is powered by a 12v Gell cell, there is a 12v festoon bulb in circuit, it is running about 15% brightness, all electronic parts are cool to touch, sorry the photo is blurred.

I attatched my cro to the output, and here is the waveforms.
The bottom line represents 0 volts DC
The top line represents the 12v DC
The small top section which appears above the blank lower section represents the amount of time that 12v DC is being fed to the armature of the DC Motor
As this small top line gets wider, it tells us there is more 12v DC alowed to flow through to the motor, the wider the top line becomes, the small the lower line becomes, this is what is called the mark space ratio, or, the time between the times the power is turned ON to OFF, but it is turned ON or OFF at full grunt at each on and off cycle.

2969 = At about 15% power being delivered to the bulb
2971 = About 70% power is being delivered to the bulb
2972 = About 80% power, the top line is blury, it's an old 2nd hand scope

jim