Re: pie pan toroids

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "R Heidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

on 10/13/01 1:06 PM, Tesla list at tesla-at-pupman-dot-com wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <Parpp807-at-aol-dot-com>
> 
> Hi all,
> I have just completed two toroids for the ends of my 48 inch bipolar. This is
> a first
> time for me so I am hoping for some input from the list.
> 
> The aluminum ducting is a 4 inch ID Super-flex from McMaster-Carr, item #
> 5525K44.
> Thirty dollars gets you a 2.5 ft length of the stuff that can be expanded
> to 30 feet. Not a misprint.
> 
> I formed two toroids of a 16 inch OD. Cutting the aluminum with a scissors is
> easy enuff
> even tho this is a very heavy foil. The problem is getting an even cut as you
> cut across
> the pleating. I am going to need much more practice at that. I bot two rubber
> pipe couplings for inside the toroids to join the two ends. The pipe
> couplings are a semi-
> hard rubber. They are made for joining two pieces of pvc or cast iron pipe.
> They come with 
> two of the stainless steel "worm-drive" clamps that you will have leftover
> for your
> collection of general stuff. I bot the couplings for a 3 inch pipe. That's
> the ID, but the walls          of the couplings are at least 5/16 thick and
> the whole thing fits neatly into the 4 inch ID ducting.
> Bringing the two ends of the ducting to form a neat joint is a problem. I
> drilled thru the
> ducting and into the rubber insert. I tapped the holes for 6-32 MSs. I used
> nylon screws, but I doubt that is necessary. The finished joint between the
> two ends of the toroid
> is very far from being neat. Actually, I don't like it. I wrapped some
> aluminum foil
> around it but I am going to have to see how much corona spits out from the
> joint.   
> I will know more, later.
> 
> The bipolar coil is horizontal. The 16 inch OD toroid mounts on the 1/4 - 20
> end studs of the coil. I used two aluminum pie pans as sort of hub caps to
> fit the ID of the toroids.
> Sort of like the toroid is the tire and the pie pans are the wheel so the
> flare-out of 
> the pie pan faces outward. I put a large piece of thin acrylic against the
> face of each
> pie pan to distribute the pressure over the surface of the aluminum pan. A
> 1/4-20
> brass nut  squeezes the whole contraption together. As the nut tightens, the
> pie pans 
> seat against the toroid and the monster goes into a true round shape.
> Neat like nuthin.  :-))
> 
> It now remains to be seen how much corona is going to be spitting out of the
> joint between the two ends of the ducting. I'm afraid there is going to be a
> problem with
> that.
> 
> Cheers,
> Ralph Zekelman
> 

I made my toroid in a similar manner. Imade the end of the ducting flat with
pliers then crimped the flat end like stove pipe and slid the crimped end
inside the non crimped endto fit tight. I then used a few drops of epoxi to
lock the ends together. I then filled the center with two pie pans like a
wheel with a 3 in brass toilet bowel bolt to mount and secure everything
together on the end of my coil.
     Robert H