Re: Rotary Gap

From: 	Steve Falco[SMTP:sfalco-at-worldnet.att-dot-net]
Sent: 	Tuesday, August 05, 1997 6:27 AM
To: 	Tesla List
Subject: 	Re: Rotary Gap

> >    Thanks for keeping me out of harms way! The only place that I have
> > found that sells G-10 is a plastics company that I buy my poly, and
> > epoxy from. They only sell the stuff in 24" x 48" sheets, and the
> > price
> > works out to several hundred dollars! Sooo I'll probably use lexan.
> > Thanks for your help!

Folks may well cringe at the idea, but several years ago I built a "side
grinder".  This is a 1/4" thick, 8" diameter cutoff-wheel (normally used
for sawing through I-beams) glued to a wheel I made of 3/4" marine-grade
mahogany plywood.  The plywood is glued to a pulley, and #10 bolt are
used, with vibration-proof nuts to beef up the joint between the plywood
and pulley.

The whole thing (which weighs a few pounds at least), is mounted on a
small motor and spun at 1725 RPM.  You use the face of the cutoff wheel
for sharpening knives etc.  I've used it for years with no sign of
impending failure.

The point of the above story, is that a spark gap can probably be built
using relatively cheap plywood.  The marine grade mahogany is excellent,
because it has no internal voids, uses a very tough glue in the
laminating process, and is very finely grained.  I spun my wheel in a
lathe and used a Dremel tool to true up the outside edge.  The plywood
has to be bought by the sheet, but can be used for many other projects
as well.  It is beautiful stuff for cabinet work.

Varnish would probably be desirable for a spark gap to provide more
insulation.  I may try it once I get my caps built.

	Steve Falco