Re: Toroid construction

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

Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-qwest-dot-net>" <f-h-at-c.dk>

Ed, all!

This is how I made invisible joints:

First notice how the whole duct is made out of a continous spiral of 4-5
ridges assembled by a swaged joint.

Please view in a fixed-width font such as Courier.


  X        X                        X         X
 / \      / \                      / \       / \
/   \    /   \   ----------+      /   \     /   \
     \  /     \ /   +------|     /     \   /     \
      \/       X    | -----+    /       \ /
                    +----------/         X
Something like this.

Try to tear a turn, or so, off, to get accustomed with the feel of doing
that, and notice how the swaged joint opens up.
  

  X        X
 / \      / \
/   \    /   \   ----------+
     \  /     \ /          \
      \/       X            \
                             \
                              \
                               \

 Also practice how to gently close the joint again: carefull, you can
cut your fingers real easy, here.



  X        X
 / \      / \
/   \    /   \   ----------+
     \  /     \ / ---------+
      \/       X




Now, with the toroid more or less bent to shape, tear off one full turn,
then cut at the inside equator, with a scissors. don`t worry about
compressing the ridges, and all, this is on the inside of the toroid,
where nothing is seen.

Gently fold the joint back as shown above, on each end of the toroid.

Now comes the fine detail:

Keeping pieces of tape ready, gently eaze the one end of the toroid
_into_ the other end of it, so that the part of the spiral which _were_
the joint before now rest one inside the other, like this:



  X        X                         X       X
 / \      / \                       / \     / \
/   \    /   \   ----------+       /   \   /   \
     \  /     \ / ---------+      /     \ /     \
      \/       X  +---------------       X       \
                  +---------

Make sure to fix the joint with tape, untill you have fondled the joint
into a close fit. Then introduce some 10sec. glue into the joint, and
presto! in no time, you have a solid toroid that you can handle without
it falls apart. Perhaps better wait a hour or so, for the
isocyanoacryllate to set.

Look at :

Http://home5.inet.tele.dk/f-hammer/tesla/museum/topload/topload.htm

for pictures.

Cheers, Finn Hammer


Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Esondrmn-at-aol-dot-com>
> 
> I could use some advise from those of you who have made toroids using
> semi-rigid flexible aluminum ducting.  I have two 9" metal pie pans that I
> plan to use back to back, then wrap the ducting around the outside.  When I
> made some larger toroids for the big coil using corrugated plastic pipe, I
> wrapped it around an acrylic center form and cut the ends to join smoothly
> then used nylon lacing cord to tie the ends together.  How do you join the
> ends of the aluminum ducting?  Use aluminum tape?  I planned to use aluminum
> tape to attach the ducting to the pie plates.  I will drill a 1/4" hole in
> the center of the pie plates for mounting on the coil.  Do you also maybe
> rivet the plates together?  Do you stretch the ducting out to its full length
> then cut the ends to fit?  Or, compress it back together, evenly, until it is
> just the right length?
> 
> Thanks for the help, Ed Sonderman