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Re: Touchy toroids

Subject: 
            Re: [Fwd: Touchy toroids]
       Date: 
            Sat, 15 Mar 1997 09:28:54 -0800
       From: 
            Skip Greiner <sgreiner-at-wwnet-dot-com>
Organization: 
            Greiner, Ltd.
         To: 
            Tesla List <tesla-at-pupman-dot-com>
 References: 
            1


Tesla List wrote:
> 
> Subject: Touchy toroids
> Date: Thu, 13 Mar 1997 07:55:57 -0500 (EST)
> From: tesla-at-america-dot-com (Bob Schumann)
> To: tesla-at-pupman-dot-com
> 
> Howdy coilers
> 
> I would like some feedback as to what others have done with
> their toroid construction using the available aluminum dryer
> ducting from the hardware stores. I am presently on my 5th one.
> 
> My last one was my best one but it fell off recently and landed
> on the sharp pointed acrylic inverted-cone primary forms. It was
> toast. The way I had built it was by using some 40 pound monofilamnet
> fishing line and 'chain stiched' the ducting 2 ends together. All
> seemed okay but the fishing line was above the outside surface of the
> seam, so I smoothed aluminum tape around the seam and that seemed ok.
> For the center, I cut out a circle from the center of a cheap pie
> pan and drilled 4 holes in this metal disc at 12, 3, 6 and 9 o'clock.
> I used 4 titanum (free) wires and wrapped each wire around the toroid
> and locked it in place at the center disc with those little screw locks
> used to tighten on automobile throttle cables during adjustment.
> 
> I just bought my new ducting. I came of with a stiching method that
> makes the toroid appear seamless. It is very hard to tell where the
> joining took place. There is no need to smmoth aluminum tape over the
> joint.
> 
> Ok now for the question (sorry it took so long to get here)
> 
> What other methods can I use for a center ?
> 
> Someone had told me of 2 pie pans back-to-back but I can't imagine
> how the ducting will stay on the pans' edges. I find my self looking
> in kitchen stores and department stores and hardware stores looking
> for something to jump out at me. Service people at these stores ask me
> 'Can I help you find something?' or "What are you looking for?'.
> 
> I always tell them that I will know what it is when I see it!
> 
> Thanks,
> 
> Bob Schumann
> 
> tesla-at-america-dot-com
> http://www.america-dot-com/~tesla


Hi Bob

I have used any material which is stiff enough to support the toroid
such as thin plywood, masonite, and sheet aluminum. I generally form the
toroid and then cut the stiffener to the correct size, which just fits
inside the toroid. I support the stiffener in place in the toroid on
some sort of block to keep it square. I then use aluminum glue,
available in tubes which is used to bind aluminum, to bind the stiffener
to the toroid. I merely lay a bead of aluminum glue along the mating
surface between the stiffener and the toroid. When this is dry, I turn
over the assembly and apply a bead to the other side. The whole thing
ends up to be very stable and strong. Aluminum tape is used to connect
the center hole to the toroid if an insulating material has been used
for the stiffener.

Skip