DIY Coil Winder

[wombweller]

Hi

Recantly I posted a thread seeking advice on a Synchronous clock motor anyway this lead me in to rewinding a new coil.
https://www.electro-tech-online.com/threads/very-old-electromagnet-advice-needed.106212/#post873862

I have now decided to TRY and make my own coil winding machine as I intend to wind more coils in the future.

I wanted to ask for ideas on how to construct a decant winder.I looked on Youtube for inspiration but most winders I found were too basic for what I wanted.

The two main challenges I am looking at are-
Motor speed control, forward and reverse.
A system where a guide arm forces the wire along the bobbin and forces it to return back when it reaches the other end of the bobbin.

The counting system I could use electronic components but if I were to be very choosy I would like a CNC. version.

Any help and advice will be much appreciated.

Cheers!

 

[mneary]

If you know the wire gauge and dimensions of the spool, or the length, or the weight, of the wire, then the number of turns is an outcome. You could alternatively use DC resistance but that requires damaging the insulation.

My first choice would be a scale. I would weigh the wire supply roll before starting and wind until I've removed the proper amount. I would confirm before the final cut by measuring DC resistance.

 

[Reloadron]

Just off the cuff the coil winding machines I have worked with use much larger diameter wire than you are looking at but the principal seems the same on most machines I have seen.

The rotational speed of the bobbin is controlled by a foot switch or can be preset. The motor is a stepper motor driving a gear network and there is a turns counter. Count to N and halt.

The back and forth across the bobbin is again a stepper geared to a lead screw configuration. Travel can be reversed using either micro switches to reverse the motor or pre programed so travel is reversed after counting N number of pulses to the stepper.

About 10 years ago I had a small coil for a solenoid burn up, much like the coil you had. The only thing I was pretty sure of was the wire gauge was AWG 30. The part was obsolete and no longer made. I rebuilt the bobbin, got some kapton tape and dragged the mess to the machine shop. I chucked up my bobbin and slowly wound off a large spool of AWG 30 magnet wire and figured good enough. That coil ran flawless and cool another 7 years till the system was finally replaced. Go figure huh?

Ron

 

[BobW]

Try googling "Gingery coil winder"
You'll get lots of hit for a DIY coil winder that's suitable for winding small coils with fine wire.

See also video:
https://www.youtube.com/watch?v=FIOocMoRsYQ

 

[Reloadron]

That video was really slick and I liked the background music. I really, really liked his coil winding machine. Talk about some cool homebrew!

Thanks for posting that.

Ron

 

[wombweller]

Hi All

I've seen a few good videos of homebrew winders but not all include a traverse guide to make sure the coil ends up neat.
YouTube - Guitar pickup winder, coil winder, automatic traversal
YouTube - Guitar Pickup Winder (wish the Schema was available for this)
YouTube - Auto traverse pickup winder

The Three main area's are
Speed of the bobbin
Traverse
Turn count

For the turn count and without the use of a PIC. we can use a few 4026 IC's and 7 seg.displays with an Hall effect sensor with a magnet attached to a cam on the bobbin spindle.
For the bobbin a DPDT switch for the motor direction with a POT for the speed.
The traverse the only thing that jumps out at the moment that looks ok is the grooved spindle with limit switches that also switch of motor reverse.

The best way would be to use a PIC. to control all that.

Any other idea's?

 

[ericgibbs]

Morning Mark,
I am puzzled why you want a reversing function on a coil winder.??

 

[wombweller]

Morning Mark,
I am puzzled why you want a reversing function on a coil winder.??

Morning Eric

Glad to hear your puzzled but Bet not more that I am though

Well it might not be really needed but while doing test runs via my Pultra Lathe by hand on more occasions than I can count I just got too giddy and the wire ended up all over the bobbin.For me to make good this birds nest I was able to put my lathe in reverse and it just made the unwinding a little easier.

Did you see my New bobbin? I made this with plastic as you suggested but I used very good Super glue to stick it all together, not come out too bad!!


I want to make this work well as I know I have plenty of coils to make and rewind.

Cheeeers!!

 

[wombweller]

That video was really slick and I liked the background music. I really, really liked his coil winding machine. Talk about some cool homebrew!

Thanks for posting that.

Ron

Hi Ron
Thanks for participating!!! It is slick!! there are a few people that have gone to some degree to make their winders.I want to also as I see it as a permanent workshop piece of machinery that will have lots of use.One of the best searches I've found that come up with good results is 'pick up coil winder' these Guitar people really want their coils to be good.

Cheers!!

 

[Pommie]

YouTube - Guitar Pickup Winder (wish the Schema was available for this)
The best way would be to use a PIC. to control all that.

I'm sure that the forum could come up with a schematic for that and the pic code could be seen as an interesting challenge to some.

Edit, just watched the ham radio winder. That is just so impressive.

Mike.

 

[wombweller]

I'm sure that the forum could come up with a schematic for that and the pic code could be seen as an interesting challenge to some.

Edit, just watched the ham radio winder. That is just so impressive.

Mike.

Hi Mike

It is quite neat especially the finished coil and yet it looks so simple, perhaps I should adopt the KISS. approach. What I want in the end is a CNC. winder.

If I can get a mix of a couple say this for the main build-YouTube - Guitar Pickup Winder And this for the traverse system-YouTube - Guitar pickup winder, coil winder, automatic traversal then I would be an happy chap.

Like I said both require levels of PIC. programming to the levels that I'm not at I ought to be as I have everything required to do it.

Perhaps I will have to adopt the ham traverse system using a cam to move the arm.

Or read up on PIC. to stepper motor code's pheeew!!

Cheers!!

 

[wombweller]

Ok I think I do really think I need to look in to PIC. to stepper motor.

To outline what I'm looking at I think I should break the project up in to two parts-
1) Traverse using a stepper motor and plastic lead screw.
2) Stepper to bobbin spindle winder.

The traverse system should have adjustable limits so that the number of turns it makes will allow the wire to travel to a predetermined position, once the position is reached it then returns back and visa verse.This will allow for different length bobbins.

The bobbin motor should have speed control that also counts the turns it's made and display on an LCD. This also ought to be programmable so a predetermined amount of turns can be put in and once reached the motor will stop.

Not sure of the relationship of the bobbin speed and the traverse speed perhaps their is a ratio??

Can anyone help out ? pointers. tips, push in the right direction whatever you can help with.

Thanks to all.

 

[Reloadron]

The guitar pickup was really interesting. Watched the video twice actually. The guy clearly demonstrated creativity and he used a well thought out plan.

Initially I wondered why he bothered to use the 5 volts from the PSU for his motors then went through the trouble to regulate a 12 volt line down to 5 volts for the uC and logic circuits? Hell any 5 volt rail on an ATX PSU has more than enough current. Then it was like DUH as it hit me. NOISE! Stepper motors are notorious for feeding noise back into their power source, not a big deal if the motor is alone out there but a hell of an issue if your micro controller shares the same power source.

If I were looking to build a prototype I would use pretty much like he did, whatever I could get my paws on. The only high end items he had in there were the motors, so I would start with looking around for a few beefy stepper motors. Since the motors are the heart of things I would start with them.

He used only a single pot to control motor speed so we can figure there was behind the scenes math in his program on the PIC. The traversing speed has to be a function of the spindle speed and the wire diameter. He was winding AWG 42 wire which has a diameter of .0025" so for a 1" bobbin that is 400 turns. Traveling 1" in .0025" increments. Anyone catch the screw he was using?

I would be looking at stepper motors capable of .5 step increments.

He used dry wall screws for his reversing stops which could be made fancy and adjustable.

The video clip was full of good ideas. Not that all should be used but some could be employed with things found in the other clips.

Excellent use of Tupperware too!

I think you sit down with a nice clean white sheet of paper..........................

Ron

 

[Pommie]

Couldn't resist.

I had a circuit breadboarded that I used to teach a friend about stepper motors and so I thought I would have a play with it. This is the board,

And this is the code (in BoostC),

#include <system.h>

#pragma DATA _CONFIG, _CP_OFF & _CCP1_RB0 & _DEBUG_OFF 
        & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_OFF & _BODEN_OFF 
        & _MCLR_ON & _PWRTE_ON & _WDT_OFF & _INTRC_IO

#pragma CLOCK_FREQ 4000000

unsigned char PK2_reserved@0x70;
rom char *table={0b1000,0b1010,0b0010,0b0110,
                  0b0100,0b0101,0b0001,0b1001};

void main(){ 
unsigned char i,pos,temp,direction;
    osccon=0x62;            //4 meg
    ansel=0;                //no analogue
    trisb=0b11000001;       //B1-B5 output
    direction=1;            //first go clockwise
    pos=0;                  //start at zero
    while(1){                   //loop forever
        for(i=0;i<100;i++){     //repeat 100 times = 90 degrees
            portb&=11000001;    //zero all outputs to H-Bridge
            temp=table[pos&7];  //Get required output
            portb|=(temp<<1);   //put it on B1-B4
            portb.5=1;          //enable H-Bridge
            pos+=direction;     //move to next position
            delay_ms(4);        //small delay
            portb.5=0;          //disable H-Bridge
        }
        direction=-direction;   //reverse direction
    }
}

And this is what it does,

I set the delay at 4mS as at 1mS you couldn't see it.
The stepper is from an old Cannon printer but this size is available in lots of places. It's 200 steps per rev but I half stepped it so 90° is 100 steps. It draws 0.7A per phase and so the SN754410 easily handles it. This could all be done on a 1mS interrupt and so the main code could run a display etc.

To incorporate a second stepper to rotate the bobbin would be relatively easy and so a coil winder should be doable.

Mike.
P.S. Just noticed I put ISP on the picture. It should be ICSP. Maybe InCircuit should be one word.

 

[wombweller]

Hi Mike

Great work.

I will scan through and see if I can make sense of it all

So you have it automatically running it both directions can this be easily adapted to work from push buttons to set the limits?

I will give this my all as it's a very useful project BUT I have to be honest and say my coding skills are very limited.

If I were to purchase some components would you be willing to help out with the code when I get stuck as I'm very sure I will????

First off can we put together a shopping list so I can order!

Key pad
LCD.
2 stepper motors (what type)
SN754410
16F88 PIC.
?

Thanks for the very helpful input.!!

 

[Reloadron]

Hi Mark

If you are in the US I can help you out with a keypad. Yours for the asking if you can use it, postage on me. Not sure where it came from, it has been sitting in a draw about 20 years, looks exactly like the one in the guitar pickup video. Never used it and if I haven't used it in 20 years I doubt I'll have a need for it anytime soon.

Mike

Really nice and no shortage of steps!

Ron

 

[Pommie]

Mark,

To run an LCD, keypad and 2 H-Bridges I would use a slightly bigger pic. The LCD and keypad require 10 I/O pins and the H-bridges 5 each for a total of 20. The 16F886 has 24 and so would be ideal. For an LCD I would go for a 4*20 one as it gives more room for information. Keypad can be 4*3 or 4*4. Maplin do both **broken link removed** and **broken link removed**.

As for stepper motors it depends on what you can get. I found these at Sparkfun. They are ideal because they only draw 0.33A and so can easily be driven with the SN754410. Have a look what you can find that has a coil resistance of at least 24Ω. Another possibility is to switch to a 5 wire stepper and use individual mosfets for each coil.

Sure, I'll help out with the code. Just ask away.

Mike.

 

[wombweller]

Hi Mark

If you are in the US I can help you out with a keypad. Yours for the asking if you can use it, postage on me. Not sure where it came from, it has been sitting in a draw about 20 years, looks exactly like the one in the guitar pickup video. Never used it and if I haven't used it in 20 years I doubt I'll have a need for it anytime soon.

Ron

Hi Ron and thanks for the very kind offer, but I am in the UK. but thanks anyway

Regards
Mark

 

[wombweller]

Mark,

To run an LCD, keypad and 2 H-Bridges I would use a slightly bigger pic. The LCD and keypad require 10 I/O pins and the H-bridges 5 each for a total of 20. The 16F886 has 24 and so would be ideal. For an LCD I would go for a 4*20 one as it gives more room for information. Keypad can be 4*3 or 4*4. Maplin do both **broken link removed** and **broken link removed**.

As for stepper motors it depends on what you can get. I found these at Sparkfun. They are ideal because they only draw 0.33A and so can easily be driven with the SN754410. Have a look what you can find that has a coil resistance of at least 24Ω. Another possibility is to switch to a 5 wire stepper and use individual mosfets for each coil.

Sure, I'll help out with the code. Just ask away.

Mike.

Hi Mike
Thank You very much for the input to this project, it's very much appreciated

Maplins is good as just down the road from me but as usual they don't stock some things that I need like the Stepper items. I am now looking for a UK supplier for similar to those from sparkfun.

Will get back.

Cheers Mark

 

[MrDEB]

I am still wondering WHY use a D flip flop?
Couldn't he have just used the push-buttons to input a LOW signal into the pic?
YES great use of tuipperware.