[TCML] G-10 blistering

["David Rieben" <drieben@xxxxxxxxxxx>]

HI all,

I figure the answer is that I am just pushing a bit too much
power for the size of the flying electrodes of my ARSG of
my Green Monster Tesla coil, but I am going to go ahead
and share my experience with the list. I recently upgraded
my Green Monster coil's ARSG to 2 pair of stationary elec-
trodes spaced 180 apart on each side of the rotary disc 
instead of a single pair of stationary electrodes. The reason
for adding a second pair of stationary electrodes is that I
was getting deminished quenching at power levels over
about 60 amps draw that was apparent with flaming "pop-
ping" yellowish plasma at the ARSG spark along with some-
accompanying erratic spark output and spikes in the current
draw, according to the panel ammeter. Adding the second
set of stationary electrodes made for a marked improvement 
in this and I am now able to run at up to 90 amps input 
(at 240 volts) continuously without a hitch. However, I noticed 
a strange "hot melted pastic" like odor after the last long
run at a solid 90 amps input when I got close to the tank cir-
cuit assembly after powering it down. I couldn't figure out 
exactly what was causing the odor at that time but a closer
examination a couple of weeks later revealed that the G-10 
disc had actually scorched and blistered a bit around each
of the (8) 3/8" x 1.5" long solid tungsten flying electrodes.
I supposed that sustained 90 amp runs are just taxing the
thermal dissipational characteristics of my ARSG componenets
to their limits? Also, I believe the addition of the extra pair of
stationary electrodes has increased the thermal load 
on the flying electrodes since they are now "sparking" twice with 
each disc revolution instead of once. BTW, the (4) stationary 
electrodes are each 1/2" x 3" long solid tungsten rods set in 
1.25" x 2.5" long brass square stock. I suppose I'll have to up-
grade to more massive flying electrodes if I wish to run at 90
amp long runs on a regular basis. Other than the excessive flying
electrode heat, which are whirling at over 3000 RPM, the coil
is running great ;^))  Here is short video clip of it 
running BEFORE the ARSG modifications:
http://youtube.com/watch?v=eWZD3M-nye8
It runs notably smoother now without any racing sparks
and at even higher power levels than I was able to run
for this clip. Will the flying eledtrodes eventually burn their
way out of the G-10 disc since they actually got hot enough
to scorch the epoxy bonding agent of the G-10? Comments 
from others with high powered coil experience is welcomed.... :^)

David Rieben
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