Re: Rotary's

Hi Bob,

Comments interspersed.

> Original Poster: bob golding <yubba-at-clara-dot-net>
> Hi all,
> I have found some material to make a rotary gap with. It is
>some sort of fibre glass and resin based material. It was
>off the top of a 3 phase transformer ,and carried the
>connections. It was hard to cut with the jigsaw and stank to
>high heaven when I was cutting it.

Hey, that sounds quite like G-10. Is it greenish in color?

>On to my point,I have managed to get two pieces 5" in
>diameter out of it and am wondering what would be the
>best way to go. Should I go for 2 pole or 4 pole? I am
> going to use it with my 2.2 kva radar tranny. I have yet
>to get the motor and decide on a secondary size. I have
>enough caps to get up to 46nF and the rating of the
>tranny is 8200 volts.

This decision depends on three things:
a.) What will the speed of the motor be?
b.) What bps are you planning to run?
c.) How will your RSG be constructed?

To a & b: Here are the possible combos:

1.) 2 electrodes and 3000 rpm: (3000/60*2) = 100 bps
2.) 2 electrodes and 1500 rpm: (1500/60*2) = 50 bps
3.) 4 electrodes and 3000 rpm: (3000/60*4) = 200 bps
4.) 4 electrodes and 1500 rpm: (1500/60*4) = 100 bps

Forget case #2. You will blow your caps or your safety gap
wonīt stop firing. Any of the other possibilities is okay. You,
however, might want to "prefer" case # 3, because your
cap (~3 Joules) is on the small side for a 2.2kVA xformer
(~270mA-at-8200V), so the 200 bps rate might get you better
results AND the time between firings is cut down to one half.
This will be *safer* for your caps.

To c:) 5" in diameter is a small disk. You might want to build
your RSG a bit different than most do. *Normally*, the RSG
electrodes go through the disk and are isolated from one
another. One (or more) stationary electrode is in front of the
disk and the second is behind the disk. If I were you, I would
interconnect all rotating electrodes and make the pick up from
the front. That way, you donīt have to worry about the arc
jumping from isolated to isolated electrode on the disk.

Coiler greets from Germany,