Re: Toroid construction hints

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

Original poster: John <fireba8104-at-yahoo-dot-com> 

Hello fellow coilers,
It seems most of us have a love-hate relationship with corrugated ducting. 
This relationship is understandable,they're cheap but they dent with ease. 
I for one, can feel sympathetic to those who have lost a decent topload to 
this annoyance. I have felt your pain! My first topload was the standard 
corrugated ducting, and as you may have already divined, it looked like a 
boxer after 15 rounds. In order to cure my woes, I decided to try an 
experiment. Instead of using rigid corrugated ducting I procured the 
flexible type. The topload was constructed with the use of a center disk 
for spacing and aluminum tape for support. Without conviction, I can say 
that this topload has been to my floor and back many a time. A bad picture 
is 
at 
<http://www.geocities-dot-com/fireba8104/topload01.jpg>http://www.geocities-dot-com/fireba8104/topload01.jpg 
.
Enjoy,
John

Tesla list <tesla-at-pupman-dot-com> wrote:
Original poster: FutureT-at-aol-dot-com
In a message dated 2/13/04 10:16:40 AM Eastern Standard Time,
tesla-at-pupman-dot-com writes:
Ian,
There is a wonderful way to join the ends of corregated ducting.
I don't use any tape or covering. I simply cut the ends as evenly
as possible so no metal sticks up. Then I cut a piece of wood
that fits into the ends of the ducting. This wood should be
specially shaped with a double curve of sorts. The wood is a
round plug basically, but has another curve in it which lets
the joint curve to the same degree as the rest of the toroid.
This wooden plug should be 1.5" thick. Half of the plug enters
one end of the ducting, and the other half enters the other
ducting end. Next tiny nails (brads) are pressed through
the ducting between the ribs and into the wood. About 10
nails are used. The heads of t! he nails fit beween the
ribs of the ducting. Use a punch to hammer the nails below
the ducting rib surface so you don't dent the ducting. If done
correctly, this joint will not show, and will not preferentially
break out with sparks.
John

 >? I thought I had smoothed the tape out
 >pretty well, but it is certainly not as uniform as the ducting itself. Any
 >ideas anyone how I can improve this situation ?
 >
 >Ian
 >Ian.
 >