Re: Large Tesla Coil Construction Details - Comments Requested

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

At 11:38 AM 7/29/2005, you wrote:
> Original poster: BunnyKiller <bunikllr@xxxxxxx>
>
> I tried the "wringer roller" approach and found it to be tedious, 
> almost impossible to control the curling and mildly costly..
>
> I made my own wringer first and had poor results, the rollers NEED 
> to be exactly parallel tangentally in both X and Y positions. The 
> next effort was done at work in the metal shop ( they have a real 
> roller there) and you need to have the tube as straight as possible 
> and as close to perpendicular to the rollers to avoid the "curl" effect.
>
> All I have now is 2 rolls of wavy flattened Cu tubing rolled up in 
> the corner of the shop....
>
> Scot D


Given that a big part of the tubing cost is the cost of copper, you'd 
probably be better off buying the same amount of copper as strip of 
1"x1/8" or 1"x1/16" copper, and then rounding the edges with a 
suitable tool. A router with a "really, really" sharp blade, and 
using a suitable lubricant (I understand that condensed milk works 
well on copper.. an emulsion of oil and water, essentially)

You might need to buy a number of lengths of the copper bar, and bend 
them to the right radius (for which a standard 3 roll bender would 
work just fine) and braze/solder them end to end.

CBC (which is part of Parawire, a maker of colored craft wire, which, 
as several on the list have pointed out is NOT magnet wire) sells 
copper strip in thicknesses from 0.008" to 0.125", any width. 
http://www.parawire.com/copper.html

Phelps Dodge (who mine and refine the stuff) say they make copper 
strip in widths from 1-3.5" in thicknesses from 0.030" to 
0.312".  Even more interesting is that they make "flat copper wire" 
in widths from 1/8" to 1", in the same range of thicknesses, and 
here's the best part, with "rolled edge".  Probably comes in a 50 lb 
reel minimum, though. You'll need to find a distributor.

You might also look at their listings for "trolley wire", which has a 
grooved or oval cross section.  (and might be something to call 
around about.  I'll bet electric trolley/train systems periodically 
replace their wiring, and have spool ends, etc.)
http://www.pdhpc.com/SpecialtyCopperProducts/SpecialtyAlloyWires_Shapes/CopperStrip.htm




> Tesla list wrote:
>
> > Original poster: "S&JY" <youngsters@xxxxxxxxxxxxxxx>
> >
> > I would like to see someone succeed in flattening copper tubing into a flat
> > ribbon.  I am thinking a couple of powered steel rollers, "wringer style",
> > would work, with some decent guides into and out of the rollers to ensure
> > you don't produce a wavey mess.  Flattened tubing would be ideal because the
> > edges would be rounded and less prone to produce corona than brass ribbon,
> > and the copper would conduct much better, of course.  Anyone up to the
> > challenge?
> > --Steve Y.