Re: building primaries

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

Original poster: "Bill Vanyo by way of Terry Fritz <twftesla-at-qwest-dot-net>" <vanyo-at-echoes-dot-net>

If I understand the question, ...

HDPE = Polyethylene cutting board, from your local Kmart, Walmart,
whatever.  This page: http://hometown.aol-dot-com/kze/vitem-2.htm
has polyethlene cutting boards at decent prices (18" x 30" x 1/2" for
$18.00), though I've always got mine at the local dept. store.

I did once buy some "poly" cutting boards at Walmart that were not
polyethylene, but some other kind of white plastic (melted when cut -
useless).

The beauty of polyethylene is:
1) It's a pure pleasure to machine.  Cuts like butter.  When you drill
it, instead of plastic sawdust, you get these two long curly pieces of
plastic.  Drill 100 holes, and you can pick up the mess (200 identical
long curly pieces) with your fingers.  It's really neat.
2) It's a decent insulator.
3) It's durable.
4) It looks nice - a nice clean white.
5) It has a relatively low coefficient of friction (slippery).

Only possible downside is you can't glue it.  I don't think there's a
glue that sticks to it.  Actually, this is useful.  When you're using
epoxy or whatever type of glue, leave polyethylene sheet under your
work, so if anything drips, you won't have glued your work to whatever
it's resting on.

BTW, HDPE = high density polyethylene (typical white plastic cutting
board material)

I used a 17/64" drill bit for the holes in my HDPE supports (drilled
holes 1/2" apart), to fit 1/4" copper tubing rather snugly, but still
able to slide the supports over the tubes.  

	- Bill

Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<RQBauzon-at-aol-dot-com>
> 
> HDPE supports? spacers? where do you get that?