[Prev][Next][Index][Thread]
Whoah Stop!! (was Re: The demonic Rotary spark gap)
Hello Chris,
>Original Poster: "christopher boden" <chrisboden-at-hotmail-dot-com>
>
>Alright....I yeild. I shall attempt to build a rotary gap.
>
>I've seen a design for one on the Tesla Research site...I believe
>it's in the pics for the Model 8 or 12. It looks like a motor
>spinning a 10 or 12" phenolic disk with about 8 electrodes mounted
>around the periphery. There's an electrode with terminal at either
>side on the back (motor side) of the disk. And a shorting bar with
>electrodes across the front of the disk.
>This looks to be the simplest type of rotary I've seen and I can
>build one (after finding the right electrodes) in a couple hours.
SCREEEEEEEETCH. STOOOOOOOOOOPPPPPPPPPP!!!!!!!!
Chris, let me put on the brakes for a minute. I have been scanning
across your posts. You seem to be jumping from one coil design
to another. While I sure donīt mean to insult you, I would suggest
you start out with a SMALL OBIT or NST powered coil. Stay away
from rotaries, pole pigs and high power equipment until you have
a feel for high voltage things (and forget about dangerous notions
like trusting/using those HV gloves). Just giving a coil "more juice"
(i.e: w/o some knowledge of what you are doing) will not increase
the spark length too much and will decrease the lifetime of some
(very expensive) components.
For a beginning coiler, the max spark length should be of NO
importance at all. You want to learn something. A multi-kW,
-larger-than-your-house- coil is definately NOT the way to start.
The first coil I built (with the help of my dad) at the age of 12 (which
seems to be THE magical TC age, right Fr. Tom/Richard Hull?) was
powered by a 15kV/30mA NST. My max spark length was around 6",
which isnīt too hot. But I didnīt care. I was so happy that it worked,
that the spark length didnīt matter to me. It did take me 15 years to
get back to coiling, but my present 8" coil (powered by a 600VA NST)
is spitting out 50+ (and I might be able to squeeze out a few more)
inches.
BTW: I am using a static gap and not a rotary (yet).
While a rotary IS nothing more than a spinning disk, it takes very
good machine skills to build one. Machining tolerances are in the
0.005"-0.001" range. If you have never worked with these tolerances
before, you will have a hard time building a RSG. Another VERY
important part in building a RSG is an accurate balancing of all parts,
otherwise your bearings will say good-bye after a few runs. A single
static(!) gram of imbalance WILL amount to many pounds at running
speed. If you have ever witnessed a small grinding disk shattering,
you can see what dangers are involved in the construction/operation
of a RSG (and a grinding disk has fibers inside, which will slow down
the pieces before they are flung around) You MUST realize that you
just canīt "slap it together" in an afternoon (totally forget about "a
couple of hours"). The "construction" (I mean just thoughts about it)
will take you a couple of hours at least.
Depending on your xformer, you can use a SRSG or an ASRSG. Electrode
material depends on your budget and your input power. You could (I donīt
recommend it) even use Magnesium, because solid Mg is nearly impossible
to ignite (it takes small filings or powder to get a fire started). As a
matter of fact, you can even (TIG) weld Mg.
My true bottom line advice for you is:
-----------------------------------------------
Start with a small coil, enjoy it, learn by doing and live longer. Then,
after you get confident (but NOT careless), slowly work your way
up the spark length ladder. There is absolutly NOTHING wrong with
small sparks and ONLY an "alive" coiler is a good coiler................
Trash the HV gloves (and the belief in them), find yourself a good
friend (that you really can trust), learn about switching off the
power, shorting caps, never trusting anything (esp. not yourself),
which means checking, double checking and giving things another
look over BEFORE assuming ANYTHING. HV equipment does NOT
forgive. At the voltage levels we (coilers) run, electrons like to
"come out" and say "Good afternoon" For a good spark output you
need a pretty thorough understanding of the how-and-why. This is
an absolute neccesity in order to build, operate and tune a Tesla
coil (esp for high powered equipment) properly. The internet and
people like Terry Fritz, John Freau, John Couture, Richard Hull
and all on the list are THE best source for TC construction. The
information available is very wide. It ranges from simple plans
to the very complex how and why of a TC.
Think about it.............. and PLEASE be careful.
Coiler greets from germany,
Reinhard