RE: [TCML] 5.25" SRSG tesla coil suggestions on improving performance

["John Paul Grippa" <pupman@xxxxxxxxxxxx>]

It looks to me from the pictures that your strike rail forms a complete
circle.  There should be a gap in the rail to prevent eddy currents killing
the coil's power.  Try adding a gap in the rail.  This should improve your
output.

Good luck!
JP


-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of JJ Dasher
Sent: Monday, August 05, 2013 9:59 PM
To: tesla@xxxxxxxxxx
Subject: [TCML] 5.25" SRSG tesla coil suggestions on improving performance

Hi all,
I'm new here.  Although I've built a few coils in my past, I still consider
myself a newb coiler.  I've never been the type to do things mathematically
perfect, and tend to wing it as I go along, which may be my downfall here.
 For the past couple of years on and off, I've been working on a 5.25" SRSG
coil to use in a Halloween display.  This is my largest coil so far.  You
can see it in action here:

http://www.youtube.com/watch?v=2P3T5zuT9DI


and pictures of the guts here:

http://imgur.com/a/0jgxR



I'd like to get some constructive criticism and advice on getting this
running better.  This trips my 20amp breaker after about 10-15 seconds of
running, so I figure about 2.2-2.6kw?  I'm currently getting 36" streamers,
which I feel are somewhat weak.  They are purple, and not very bright.
Specs:

Large old powerstat variac salvaged from power equipment.  Not sure on exact
specs, but I assume it should handle 30+amps with ease.  Wired for approx
150v boost.

Dual MOT's (pulled from 1200w commercial MWs), currently unballasted.  130uf
of PFC caps behind them.
180nf MMC cap built with 10 strings of 8x 942c20p15k-f's.  1m bleed
resistors installed.
SRSG is a 5" acrylic disc attached to a 1800rpm sync motor.  4 flying
electrodes for 120bps.  Electrodes are 1/8" thoriated tungsten.  Phase is
adjusted by twisting the motor in its mounts.
Primary is 3/8 copper tubing, slightly conical.  Currently tuned at about
2.25" turns Secondary is 5.25" x 24" 22awg magnet wire with a couple of
coats of poly.
Topload is a spun aluminum 4.5"x18" toroid.
All high current busses are 4awg stranded copper with large soldered lugs.

The next improvement I plan is to upgrade to 1/4" tungsten electrodes.  The
stationary electrodes currently glow red hot after about 5 seconds of
running, so I added a fan.
I'd love to get some bright long white snakes like I've seen from similar
size coils.  Please advise!

Thanks!
JJ

P.S.  There is normally a safety gap installed, It just wasn't in place when
I took those pictures.
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