Re: mishaps and oscillator former suggestion

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

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: "Christoph Bohr" <cb-at-luebke-lands.de>

 > With the beginning og the cold part of year I decided to redesign my
 > somewhat unfaithful magnifier construction from last year. To make a long
 > story short: It arced over in many places due to the unfinished wood soaked
 > up water during storage.....but the whole setup was more of an experimental
 > one...and the right time of year for bonfires

Wood near high-voltage conductors is not a great idea...

 > Now I was loking for some tube with 25 or 30cm ( about 10 to 12 inch )
 > diameter and 30cm length.
 > This is unavailable or very expensive where I live ( I would have to buy
 > much larger lenth ). Are there any ideas around for a cylindrical former?

It's not difficult to find plastic pots with this size. Maybe a garbage
can.

 > I thought of an octagonal arrangement of 8 HDPE posts made from kitchen
 > board, but this would of course result in an octagonal coil....would this
 > harm the performance...after all this could look pretty cool if built
 > properly. ( spells not built by me )

Maybe 8 thin PVC tubes, for smoother corners.

 > note to Antinio M. de Queiroz: your great inca program has become a almost
 > daily companion with such desing questions, can I take octagonal für round
 > coils...or will the results differ to much?

Calculations for coils made with straight segments is one of the things
in my list of features to add to the program. A question of organizing
some formulas. No great difference is expected from a circular coil
with the same area.

For awhile, I am working on electrostatic calculations. The program
that is now in my web site can already calculate capacitances and
electric fields for almost anything with axial symmetry, including
weird objects as toroids with elliptic cross section. I am now
adding color plots of potential and electric field.
The Inca program is at (the site was down today):
http://www.coe.ufrj.br/~acmq/programs

Antonio Carlos M. de Queiroz