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Re: Touchy toroids

Subject: 
        Re: Touchy toroids
  Date: 
        Fri, 14 Mar 1997 14:22:00 -0500
  From: 
        "Robert W. Stephens" <rwstephens-at-headwaters-dot-com>
    To: 
        tesla-at-pupman-dot-com


> Date:          Thu, 13 Mar 1997 07:55:57 -0500 (EST)
> To:            tesla-at-pupman-dot-com
> From:          tesla-at-america-dot-com (Bob Schumann)
> Subject:       Touchy toroids

> 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
> 
> 
Bob,

Get yourself a hot glue gun!  After forming the ducting into the 
desired circle size to fit my chosen center form I hot glue the ends 
together.  I then glue the donut to the center piece.  One great 
center piece is the removable lid from a 50 gallon steel oil drum.  
With 10 to 14 inch diameter duct this can make one mean topload.
I use the identical, but smaller diameter lids from those green
re-sealable 
metal cans that military equipment comes packaged in for smaller 
toploads.   I still use aluminum tape over the joint where the flexduct
joins 
itself.   To speed the cooling of the hotglue while one hand is 
applying stabilizing pressure on the joint I have a small squirrel 
cage blower set up like a hand held hair dryer.  It is used to 
quicken the setting of the joint.

This method results in a beautiful looking toroid in minimal time.  
I'd sure like to find a source of two part (like epoxy) foam that I 
could pump into these toploads to make them more dent resistant.  You 
can't play frisbee with flexduct toroids.

BTW, knitting is mostly for girls, and fishermen.

rwstephens