Re: Toroid construction

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

Original poster: "Marry Krutsch by way of Terry Fritz <twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>

Hi Ed,

	I don't stretch the ducting out all the way first.  I leave it alone
(compact form), then bend it around whatever is going to be the center. 
It stretches itself according to the size of the form, and the result is
very even.  This way it's also more ridged, and resists dents better
than fully stretched ducting.

	I don't use (not yet anyway) forms for my toroids.  I find it easier
just to bend them into a circle on a flat surface (concrete driveway). 
I then put cinderblocks in four places around toroid, which keeps its
shape while I wrestle the ends together and attach them with 5 min
epoxy.  Sometimes the cinderblocks scuff the toroid up a bit, but it
makes no difference if it's going to be covered with Al tape.  I usually
sand the ends a bit to help the epoxy stick, too.

Good Luck,
Winston K.


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