Winding a coil

[Stustoys]

Definition of scram wound please?

No control over were the wire lands.

Stuart

[neksmerj]

Just thinking outside the box, how about using an old Singer sewing machine to wind the coil? I have several old machines here, they all have a bobbin winding mechanism that feeds the thread back and forth.

Ken

[nadroj]

No control over were the wire lands.

Stuart

Ta.

Jordan

[tinkera]

I don't know how to put bits of previous posts in the reply so I will put it in brackets. [As I understand it, as long as you are only shorting winding 9998 to winding 9999 it will work just fine......... still best not to.

Stuart]
Not true, shorting any turn to another turn results in a shorted turn, fire in seconds.
tinkera.

[Stustoys]

I don't know how to put bits of previous posts in the reply

Hi tinkera,

Click "Reply With Quote, on the right below the "like". Not the "+ thats for multiy quotes.

Care to explain how one shorted turn(to the next turn) will cause a fire?

Stuart

[tinkera]

Hi tinkera,

Click "Reply With Quote, on the right below the "like". Not the "+ thats for multiy quotes.

Care to explain how one shorted turn(to the next turn) will cause a fire?

Stuart

Hi Stuart, thanks for that, got to be a good day if I learn something new.

Because a shorted turn is a closed loop around the magnetic core, it ends up getting a massive current induced into it which causes that shorted turn to get very hot, often so much that it catches fire. This heat causes the insulation of other nearby turns to fail in the same way and this process then rapidly cascades until the whole coil of wire either catches fire or the supply of current is cut.
I downloaded this from Wiki Answers, better terminology than I would have used. Have a great day, tinkera

[Stustoys]

Well that seems to make sense. I assume I'm getting my AC and DC mixed up as I assume this cant happen with DC?.....(well not at any normal switching rate)

Now I just have to forget the wrong answer and remember the right one. Which I have trouble doing sometimes

Thanks

Stuart

[tinkera]

[QUOTE=Stustoys;1685172]Well that seems to make sense. I assume I'm getting my AC and DC mixed up as I assume this cant happen with DC?.....(well not at any normal switching rate) ]


Hi Stuart, 100% correct. That's why some industrial machines use D.C. solenoid valves. now to get the smiley in the right place!

• 
  
  
  Hi Stuart, every time I try to put a smiley in it goes to the next line, What gives?

[Oldneweng]

Stuart. The fishing rod thingy is called a ferrule.

Tinkera. It appears you have something happening with the formatting of your post. The large dot, if it appears on your screen represents a line break(Enter). Don't know why. Try another post. At the end of the sentence just click on the smiley. Then wait for it to appear. At least I do!

Dean

[Stustoys]

Hi tinkera,
Thanks for that.

Hi Stuart, every time I try to put a smiley in it goes to the next line, What gives?

• Can't help with that one sorry. Sometimes the first one goes in the wrong spot but once I delete it they seem fine.
• even with "bulleted list" on

Stuart

P.s. Thanks Dean. We used tiny tungsten carbide(?) eyelets that I recall were infact for fishing rods....... I guess they are both doing pretty much the same thing.

[Oldneweng]

Thats what happened. Tinkera tried to shoot the smiley!

Dean

[bob ward]

Coming up with a scheme to accurately feed the fine wire onto the former is where my thought processes come to a halt. If it was a threading process you would be looking at a scheme that does 100 to 200 TPI, depending on wire thickness.

Its not too hard to make something geared from the drive that's turning the former to give a 100 to 200 TPI wire feed. The tricky part is when you get to the end of a run, you somehow need to reverse that gearing so that the wire then feeds in the other direction.

[weldcrazy88]

I have to wind a coil for a relay in the control box in my 10EE.... The coil is small... 22.5 OD 11mm ID and 14.5 mm wide...

it uses AWG40 wire which is tiny and has off the top of my head 10 000 turns..

I have a devious plan and have now gathered all the ingredients together I think I will need...

Candle wax, masking tape, super glue.... Hell sounds like a weekend out on the town.....

I did price getting one wound, $200....

So the plan is to make a bobbin out of candle wax, then start winding, every few turns, add some super glue, keep winding until the bobbin is full or we get the required number of turns.....

Then place the full bobbin in hot water and watch it melt away leaving your glued together coil, glue the steel centre in and tape up with electrical cloth tape and I hope to end up with a replacement coil....

Anyone foresee any problems?

Haha your "devious plan" is bound to work!

[.RC.]

I have turned up the bobbin... Was not sure of the most appropriate speed and feed for turning parrafin wax

But I was able to taker a 12mm depth of cut and there was no chatter at all....

Have put some proper electrical cloth tape as the insulator between the coil and the steel centre..... If successful the centre will be glued in with epoxy...

[.RC.]

Well first attempt has been and gone and the attempt did yield a usable coil...

Well until I remembered I had not taken any photo's, so I went get the camera and took some photo's then when I was finished, I moved away and apparently the coil tail had caught on something and it went flying onto the concrete, and now I get no measurement out of it at all... :'( :'( Yes I am a bit saddened by it as the resistance measurement was within 100ohms of what I calculated it should be... That is what happens when you do things in a poorly lit shed when you are tired at night...



So these photo's are all you will get...

I have proven the use of the candle bobbin with superglue does indeed work... Just add hot water and the candle dissolves away...

I also discovered that doing it by layer is impossible with such a small wire unless done by machine... It must have taken a lot of experimenting to build a machine that would wind the wire on a perfect layer all by mechanical linkages and gearing...

Th emethod I used was crude, the wire coil holder was improvised.. But it worked.... I ran it on at around 400rpm, moving the wire to where it needed to be by my fingers....