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Re: Primary support

In a message dated 96-02-14 17:53:37 EST, JOHN-at-link.co.nz (JOHN-NP -at- LINK *
John Timmins) writes:

>To:	esondrmn-at-aol-dot-com
>
>
>(Via unlicensed copy of UGATE)
>Hi Ed,
>
>I assume the files ES1 to ES10.JPG on the funet FTP site are yours. If so, 
>can you advise me of the supports you used for the primary coil. 
>
>Are they clear plastic triangles? 
>How is the tubing attached to it?
>Looks like pretty large diameter tube. What size is it?
>
>
>
>Thanks in advance, 
>
>John Timmins        john-at-link.co.nz

John,

Yes, the ES1 - 10 pictures are of my coil.  I put a lot of design time and
construction effort into the primary.  The vertical supports are made of .25"
acrylic.  They are designed to produce a 30 degree saucer shaped coil.  We
made a routing template to cut the raw pieces.  Then indexed them on a
bridgeport mill and cut the slots into them to hold the 3/8" diameter copper
tubing.  The slots are cut increasingly higher as you go around so the tubing
winds smoothly.  I drilled 1/8" holes through the supports under each slot.
  Then as I was laying the tubing in, I used waxed lacing cord to tie the
tubing in place at each slot/tubing junction.  The vertical acrylic supports
are bonded to a large .25" thick acrylic circle.

After I got the primary form completed, it took about 5 hours to lay and tie
the copper tubing in place.  I suspended a flat piece of plywood from the
ceiling about three feet above the coil form.  I then set the coil of tubing
on the platform and let the end drop down to the form.  Then I slid a 3/8"
tubing bender over the loose end and started forming it into place.

Ed Sonderman