how many feet...

[Southbuck]

I bought 6.7 lbs of 15awg magnet wire. It was supposed to be all on one roll. It came as 1 spool with 2.7 lbs and another spool with 4 lbs of wire on it.

After coming to a financial agreement with the seller, Im stuck with a possible splice in a coil. That I can do, but here is my question for the math wizzards.

I'm trying to find out how many feet total of wire I need per coil.

Here's my winder

http://s298.photobucket.com/albums/mm249/Southbuck7/?action=view&current=IMG_0630.jpg

So, I need it figured for 120 turns per coil. The winder has a 1x2x7/16" thick block in center.

Is it possible to figure the total feet of wire required for each coil?

Thanks
Southbuck

[Bruce S]

Southbuck;
Since you know you're possibly going to need to splice, it think it would be a good idea to measure the circumference of the outer most on your winder.
That will give you inches I'm sure, multiply that by number of turns (120) then divide by 12, that will give you feet needed.
There are mathy ways of doing this without any further works like PiR2 and such, but this is the easy way I do it.
Of course this will be worse case scenario but close enough.
Hope that helps
Bruce S

[Southbuck]

Thanks Bruce 

[Flux]

That is very much a worse case as Bruce s said. The mean length of turn should be considerably less than the outside one.

Weigh your wire, wind a coil and weigh again you should then easily be able to deduce whether you can get the full number without a splice. calculation is difficult and not particularly accurate.

Flux

[Bruce S]

That is very much a worse case as Bruce s said. The mean length of turn should be considerably less than the outside one.

Weigh your wire, wind a coil and weigh again you should then easily be able to deduce whether you can get the full number without a splice. calculation is difficult and not particularly accurate.

Flux

Flux, thanks for the update, sorry for the worst way to do this.

[fabricator]

The one sure way, wind a coil, weigh it then unwind it and measure it, you can always rewind it.

[Southbuck]

I have 4 lbs on one spool, I have 6 coils to make.
15awg is 100 feet per pound. Just trying to plan ahead and hope I can get 4 coils out of 400 feet of wire.
It takes 6" of wire to make the first layer around the 1x2 block in the center of the winder.
Its going to take 12"+ on my last wrap of wire.
The only reason Ive asked is that it looks very close to making 4 coils from 400 feet of wire.
If I can then no splice needed.

Not wanting to do it just for the fun of it.  

Thanks all
Southbuck

[fabricator]

I'm not sure how you would make a splice you could count on.

[DanG]

File a flat half-inch long on each wire so they nest slightly greater diameter and true silver solder - then smooth it down and a couple of thin coats of a heat-cured motor winding paint like glyptol... Thats just how I'd do it.

[Southbuck]

Silver solder and woven insulation tubing?

The joint would have next to no resistance.

Best I can think of.

Southbuck

[Southbuck]

Dan, that's a good idea.

Thanks.

[fabricator]

JB weld is a good coating too, it's good to 500 degrees and in thin coats it's flexible, and tough as hell.