Re: RSG Mounting Problem

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Finn Hammer <f-h-at-c.dk> 

Ian,

IŽl start from the back of your message:
 > Oh how I wish I had access to a lathe ...<

There are a lot of machine shops in Sidney and suburbs, they all have a 
lathe, and some of them are willing to do a simple one off for money, or 
beer, and not to forget: a good story, supported by pictures and conveyed 
with enthusiasm.

However:
 >my 12" diameter, 1/4 inch thick HDPE platter.<
1/4 inch is thin, but even worse: HDPE has a low melting point, so I 
strongly suggest that you get a better suited material for the disc. The 
electrodes are going to get hot during sparking conditions, and the last 
thing you want to have flying round is SRSG electrodes. And they will, as 
soon as they melt that HDPE disk, get out of alignment, hit the stationary 
electrodes, shatter and take off on a tangent, and hit.....

Better materials are fiberglass/epoxy based materials like FR4 and G10 or 
phenolic/linen based materials like tufnol etc. There may be other names to 
the latter type, since they are all trade names.

Now, about that hub: You really owe it to yourself to have one made up at 
that machine shop, but another alternative is to get a pulley for a timing 
belt or a v-belt, bolt the disk on to it and then grind the perimeter with 
a belt sander while the disk is rotated, perhaps not at full revs. to start 
with.

Hope this helps,
Cheers, Finn Hammer
http://home5.inet.tele.dk/f-hammer/tesla/tesla.htm

Tesla list wrote:
>Original poster: "Ian McLean" <ianmm-at-optusnet-dot-com.au>
>Hi everyone,
>Anyone know where I can get a hub for a half inch shaft (cheap) that I can
>use for my tungsten SRSG?  Only thing holding up it's completion.  Prefer a
>four hole connector plate on the end, and hollow all the way through, with
>grub screws.  Having lot's of trouble trying to find something I can use to
>attach to my 12" diameter, 1/4 inch thick HDPE platter.
>The motor spindle is 1/2" dia shaft with a flat down one side, ideal for a
>1/2" holed assembly with one or two grub screws.  I would prefer the hole to
>go all the way through the hub for best alignment capability.  Any ideas
>where I can get something like this anyone ?
>Oh how I wish I had access to a lathe ...
>PS: I am in Sydney, Australia.
>Thanks and regards
>Ian.
>