How to rise the secondary?

From:  FutureT-at-aol-dot-com [SMTP:FutureT-at-aol-dot-com]
Sent:  Tuesday, June 23, 1998 8:36 AM
To:  tesla-at-pupman-dot-com
Subject:  Re: How to rise the secondary?

In a message dated 98-06-23 01:38:20 EDT, you write:

<< ----------
> From:  Marco Denicolai [SMTP:marco-at-vistacom.fi]
> Sent:  Monday, June 22, 1998 12:46 AM
> To:  tesla-at-pupman-dot-com
> Subject:  How to rise the secondary?
> A construction problem to me is how to build the secondary (or the primary)
> so that one of them can be lifted in respect to the other to set up the 
> coupling. Can anybody suggest a good solution?

Marco, all,

I attach a wooden dowel to the bottom of my secondary coil, or a
2 by 4" length of lumber if it's a larger heavier secondary.  The dowel
is concentric with the secondary and protrudes downward about a
foot or so from the bottom of the secondary.  It can be attached to
the secondary bottom plate using screws and glue, etc.

Next I prepare the base of the Tesla coil by mounting a wooden
socket below the top of the base.  The base and socket is drilled or 
built to accept the dowel or 2 by 4 with a slide fit.  The socket also 
has a thumb screw through its side, which when tightened, holds the
dowel or 2 by 4 in a fixed position.  By loosening the thumb screw,
the secondary can be lifted or lowered (by hand), then the thumb
screw can be tightened to hold the secondary at the new height.

For heavy secondaries, a rack and pinion arrangement can be
attached to the dowel and socket, creating an arrangement such
as is used for focusing microscopes and telescope eyepieces.  An
added refinement would be to add an electric gear drive driving the
pinion gear so the secondary can be raised or lowered without effort,
and while the coil is producing sparks. 

Another method would be to attach a threaded rod to the bottom 
of the secondary instead of the dowel.  The threaded rod would 
screw into the Tesla coil base, and the secondary would be raised
or lowered by rotating the secondary.  This setup could also be
motorized for convenience.

John Freau