DIY Coil Winder

ericgibbs said:

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

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wombweller said:

Morning Eric

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

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you need reverse so you can wind in both directions

the wire is held in a reel behind the machine, it should come through a tensioner, and enters the traverse. the spindle rotates, TOP COMING.

then you need to add insulating tape, which you hold in your hand. stick it to the coil, and rotate the spindle, TOP GOING

grim said:

you need reverse so you can wind in both directions

the wire is held in a reel behind the machine, it should come through a tensioner, and enters the traverse. the spindle rotates, TOP COMING.

then you need to add insulating tape, which you hold in your hand. stick it to the coil, and rotate the spindle, TOP GOING

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That will over complicate the machine. The tape doesn't know the way it's wound on the coil. Winding the tape in the same direction as the wire you won't have to stop and reverse the machine, thereby unwinding the wire.

Normally a (fitting) sheet of insulating material is laid on top of a finished wire layer and winding is continued. The copper wire will hold the insulating sheet automatically.

(At least it is practiced that way in a factory I visited where neon light transformers are manufactured.)

Boncuk

Boncuk said:

That will over complicate the machine. The tape doesn't know the way it's wound on the coil. Winding the tape in the same direction as the wire you won't have to stop and reverse the machine, thereby unwinding the wire.

Normally a (fitting) sheet of insulating material is laid on top of a finished wire layer and winding is continued. The copper wire will hold the insulating sheet automatically.

(At least it is practiced that way in a factory I visited where neon light transformers are manufactured.)

Boncuk

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hi Hans,
I agree, this is the way I have seen it done, its also the way I have found that works for me.

Hello Pommie:

I´m Carlos from Portugal, and i´m not shure how to transform the file Coilwinder.c for a language like.Hex or .ASM to program Pic.
I have some pics 16F877 and Microchip send to me 18F4620, and I have a homemade programmer.
It´s funcional, but i need the file in .hex or .asm because i´m not a expert in programations or languages, i only need a machine to wind some transformmers and coils to my hobby (Tube amplifiers).
I make a coil winder from "Nuts and Volts", but has not precision, (in another reply i attached the file), it´s controled by PC, with Lpt port, an uses a VB interface.
Help me please:
Sorry bad english!

Carlos

Gday I am interested in electronics. You are asking about making a machine to lay the wire.
I come from a mechanical background There is a simple way to arrive at your answer and that is called a fleet angle If you Google fleet angle there is plenty of sights that will tell you about this setup and how to arrive at the result.
The answer is in the width of the bobbin and the distance from the Center of the bobbin this will lay the wirer the way you want it.
This is used in winch drums to prevent the wirer from bunching up.
Hope this helps
Or look at your mother's Bobbin rewind on her sewing machine this could work with a little modification,
I would like to know how you get on.
Greg

Maybe, it is not exactly like that

Hola Gregory,

Maybe the best (closest?) example you could have given was the reel associated mechanism used to spool/despool the fishing line.

Fleet angle as we know in winch drums, cranes and hoisting equipment is, as far as I know about coil winding machines, esentially 0º because you take the pain to guide the wire back and forth to keep it perpendicular to the bobbin.

Mazybe I could be wrong but from all what I've seen in real life, things work like this:

**broken link removed**

Even in some vessels, our cranes had a wire-guiding device that moved back & forth keeping that fleet angle = 0 from end to end of the drum.

Myself, at a painfully slow pace I am trying to build one of those coil winders, maybe now, just to cope with the challenge. The day I finish it, if I succeed, maybe LVDTs will be prohibited by law!!

You need a little angle there to keep each coil of wire pressed tight to the wire before it.

Tension is one of the most important factors, most coil winders use a spool brake that only allows the supply spool to rotate whent he wire tension is > than a setpoint. They use the same system in VCRs (remember those?) as a spool tensioner to keep tape tension constant.

My thoughts for a minimalist spool brake would be to mount the supply spool on the shaft of a small DC motor, and supply the DC motor with a tiny reverse voltage (adjustable regulated ie from a LM317). This will produce a reverse torque that can be dialed in with a pot by adjusting the reverse voltage.

Cool project Pommie!

Mr RB said:

My thoughts for a minimalist spool brake would be to mount the supply spool on the shaft of a small DC motor, and supply the DC motor with a tiny reverse voltage (adjustable regulated ie from a LM317). This will produce a reverse torque that can be dialed in with a pot by adjusting the reverse voltage.

Cool project Pommie!

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Hi Mr RB,

sounds plausible but won't suffice in practice I'm afraid. The tension should be the same from beginning to end of a coil. As the copper wire on the spool decreases (resulting in decreasing diameter) the torque will increase - and depending on wire diameter the wire will eventually break.

Another approach would be using a double loop between spool and coil and apply braking action there - either by applying brake power directly to the loop or to the wire itself using a "brake shoe" driven by a solenoid.

Regards

Boncuk

Good point, and I missed that totally. :embarassed:

There are a number of options. The diameter difference of the supply spool is probably only 2:1 or 2.5:1 at worst, so you could either adjust the tension as the spool gets used up or just live with a difference in tension depending on how much of the spool gets used up in that one winding job. The critical part of tension is to keep it on, the amount of tension is not as critical as long as it never lets up and the wire goes slack.

Your suggestion of a double loop or similar is good.

What about putting a small loop arm to detect tension, with an infrared sensor and controlling the reverse power to the dc supply spool motor? That would give a constant tension without the wear and friction problems of a traditional brake and possibly allows for electrical tension adjustment.

Or maybe simpler still, use the DC motor as a pinch roller with reverse DC current, with an unpowered second pinch roller. As the roller diameter is constant the wire tension is constant and now is fully electrically adjustable. With the supply spool freewheeling with a very small friction brake to prevent overrun.

I just like that idea of a reverse DC motor to provide the tension, it should be immune from that annoying problem you tend to get on coil winders where the spool brake gets dirty and goes into oscillation or gets "snaggy" etc.

Part of that problem is the tension loop arm and its high gain so being able to eliminate that would be a good improvement, and being able to set the tension electrically would be very cool on an automated CNC coil winder.

Hi Mr RB,

I applied a much simpler method for equal tension when I had to wind 1,300 turns of 0.06mm diameter enameled copper wire for a magnetic pickup for model airplane engine rpm synchronization.

I ran the wire over a felt pad with an adjustable felt pad on top. That way the wire was free of dust and was wound well.

Anyway, to obtain two usable coils I had to wind a total of eight because of torn wires when slipping the enclosure over the coil or when soldering the thick wires to the coil. (the coil wire evaporated at the first attempt to solder it. )

I got the idea to use felt since the winder motor was an ancient turn table drive with rpm adjustment achieved by a piece of felt pressing against a brass disk moving on the main shaft by centrifugal force and springs attached to a fixed ring on it.

I'll keep your idea in mind and will try to construct a fast acting and precise brake mechanism, probably using a similar technique as it is used for ABS in cars.

Regards

Boncuk

Hello, i'm Carlos and nobody answer to my questions.Why?
Well tell me if i need to pay anything to answer me.
I leave the forum and i never will come in.

Carlos

Hi Carlos,

You need to make your own new thead to ask a different question. If anyone knows the answer they will tell you.

To do this you use the button "Create New Thread".

Hi, i´m trying to make some guitar pickup but i need
to make a winder first.
Is it possible to store diferent coils "recipe" ?
What is the max speed?
Does the disply show RPM?
TIA

Pommie said:

I managed to have a play with this today and a few problems have appeared. The 16f887 is not big enough and I have severely run out of stack space - solution, ordered some 18F4620. I will run out of room with the free BoostC compiler very soon - solution, going to switch to the C18 compiler.

For anyone curious, this is what it does so far,

And the code so far is attached. It's a bit rough and I had to move the step code inline to keep within the stack limits, hence the very long interrupt. I should be able to tidy it up when the new chips arrive.

Mike.

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Hi Pommie

Any chance of the compiled hex file for the pic18f4620. My knowledge of using a C compiler, you could fit onto a pin head. I know that this is being lazy and maybe cheeky but I would like to start construction, before I get too old ( due to my lack of knowledge)

Nice design and look forward to making this project.