Re: Toroids

From: 	Chuck Curran[SMTP:ccurran-at-execpc-dot-com]
Sent: 	Wednesday, August 06, 1997 10:52 PM
To: 	Tesla List
Subject: 	Re: Toroids

Tesla List wrote:
> From:   Jay Bohn[SMTP:sunsoft-at-pacifier-dot-com]
> Sent:   Tuesday, August 05, 1997 10:55 PM
> To:     tesla-at-pupman-dot-com
> Subject:        Toroids
> I have seen quite a few of Tesla Coils topped with a metal toroid.
> Where is everyone finding these?
> Are most home brew?
> What would an alternate "Top Cap. Hat" be? (Copper toilet float)?
> I have been lurking on this list and have enjoyed the info.
> By the way, This is my first "post" ever!
> Thanks...

Hello Jay:

Welcome to the list, it's proven to be an open and friendly place where
you can normally get your questions answered very quickly.  The toroid's
have been made in a number of different ways, but I've got a favorite. 
If you go to your local hardware or building supply store you will be
able to locate the two key materials.  The first is flexible aluminum
air ducting, which looks sort of like an accordian like material.  4"
diameter sections are typically available for dryer ducts.  I've seen 6"
also in building supply stores. At Industrial Heating shops it can be
purchase to 12" and over diameters.  This is the stuff to make the
"Do-nut" part of the toroid with.  One end of this ducting is tapered in
order to plug it into the opposite end, so it fits together really
slick.  I have used RTV silicon rubber cement to hold it together and
also attach it to the center flat hub.  For the second material, I have
purchased 1" sheets of foam insulation, that is clad with aluminum foil
for my center hubs.  I simply cut out the round disk based on the design
requirements, then space it up off the floor to position it at the
center point of the flexible aluminum duct mentioned above.  I attach
one end along about a 6" length and let it dry over night, holding it in
place with all those one gallon paint cans from under the work bench, or
is it under the stairs at your house?  The next night I extend the duct
around the foam circle attaching it with RTV and then I tape the entire
duct with aluminum tape.  Just to make sure I got a real good connection
I've always layed sections of bare copper wire from the duct to the
center sheet just to make real sure there's a positive connection. 
After it's taped (to smooth out the surface) it is really very strong. 
I've got one that is 6" by 40" and another 10.5" by 56" and both have
worked great and are still in perfect shape.  The big one cost about
$64.00 to build, just as a reference point.
Hope this helps to give you a starting point.

Chuck Curran