RE: Toroid Design
A source for aluminum air duct is:
1011-T 11th Ave.
Detroit Lakes MN 56501
Their catalog shows duct from about three inches in diameter to at least 18"
in diameter. It comes collapsed in 28" lengths, which can then be stretched
out to 8-10 foot lengths. The advantage of this material is that it is
extremely light and can easily formed into a radius of whatever size you
need. I have built three toroids using this material plus foam insulation
board that comes with an aluminum foil sheet on either side. I cut out the
center disc using the foam sheet ( from a building supply store) and simply
use hot glue or RTV to attach the duct to the disc. Don't waste your time
or money on covering the duct with foil tape, it's not needed. Only do it
for esthetics. My last toroid used 15" duct which cost $32.00 per section,
just to give you a starting point for cost. I called the main office and
found a local distributor and ordered through them.
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Friday, December 18, 1998 11:14 PM
Subject: Toroid Design
Original Poster: Esondrmn-at-aol-dot-com
I have been putting off the construction of a new toroid. My present system
has produced 104" sparks to a grounded rod running at about 7 kva. This is
6.0" dia coil with one 5" x 33" dia toroid mounted 10" above the top most
winding. This toroid provides shielding to protect the top of the coil.
Sitting on top of that is an open aluminum cylinder (made out of roof
flashing) that is 20" in diameter and 14" tall. On top of that sits the
5" x 40" toroid. When I power the system up, sparks start to leave the top
toroid at about 60 % to 70 % of full power and at full power, I get multiple
sparks leaving the main toroid. I just finished some experiments with my
smaller 3.0" dia coil and was able to add enough toroid so it just breaks
at full power and produces only one discharge spark at a time. This
definitley improved the performance and I would like to achieve a similar
performance with the larger coil.
I am thinking about going to a 8" or maybe 10" x 50" toroid to replace the
existing 5" x 40". I would like comments on this. I don't want to get it
large that I can't break it out.
The two existing toroids are made from 5" diameter corrugated black plastic
drain pipe bent into a circle around a .25" thick acrylic disk. It is then
covered with clear packaging tape then aluminum foil tape. Does this same
pipe come in larger diameters like 8" or 10"? I don't think the local
building supply places carry anything larger than 5". I don't want this
to be too heavy. The coil can't support too much weight. When I built it,
thought a 4" x 14" toroid was large. Pretty funny now.