Re: 15 KVA RSG price
At 20:42 16/01/99 -0700, you wrote:
>Original Poster: Mark Finnis <mefinnis-at-medicine.adelaide.edu.au>
>At 17:06 15/01/99 -0700, Cabbott wrote:
>>Many people have been inquiring about my beautiful spark gap and its cost
>>to me. Here are the details
>... Snip ...
>>again, the picture is available here:
>>Bill Wysock is willing to give a small quantity discount if enough list
>>members need gaps just like the one i got.
>Nah ....... much rather build my own, but then I'm a little strange like
>Won't be able to match Bill's machining, but the general format has been
>I had been trying to follow the format used by Brent Turner (he didn't
>invent it I'm sure, but has some good instructive pics on his site), of
>establishing communication around an insulated disc using a peripheral
>conducing plate. See neat example ...
>In the absence of machining facilities this format is quite difficult to do
>well. There was a thread last year on using conductive rotating discs
>which were then isolated from the motor shaft, but again this sounded a
>Bill's format has a couple of advantages. One we double the number of
>moving gaps, with improved quenching and increased power handling capacity.
> This has to be better than series static gaps as cooling is included with
>I get to my new house in 2 weeks, so may be able to restart construction
>thereafter. I think a novice like me could make a fairly reasonable gap
>using this format.
>Rotating electrodes can be done various ways......
>1. Cheap. Use threaded brass rod with a retaining half-nut each side of
>the disk. If you wanted it neat the thread could easily be removed from
>the ends of the electrodes.
>2. High power. Off the shelf 4.8mm TIG tungsten electrodes are 150mm
>length & could be cut to and ground to suit. Then use grub screw retainers
>cf Bill's RSG.
>( Remember not everyone can affort tungsten. If I got two electrodes per
>150mm rod and neaded 10 rotating + 4 static, this would be 7 rods at $20
>each !!! )
>The static electrode mount at the front could easily incorporate
>Stand-off insulators are fairly easy to come by.
>All-in-all ...... much food for thought !!
>Thanks Cabbott (and Bill !!)
Have a look at http://www.velocity-dot-net/~djb/tesla/images/sparkgp2.gif
for a variation on cabbotts gap also based on a bill wysock design.