Spun aluminum toroids available in three sizes

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

Original poster: FutureT-at-aol-dot-com 

All,

I have three sizes of professional quality spun aluminum toroids available.
I pay the postage on these for shipment within the US.  International
shipping costs about $5 to $12 extra depending on the size.
1/4" mounting hole, easily enlargeable to 3/8".  These are properly
shaped and finished pristine toroids at about 1/2 the usual cost.
Strong 3003 H-14 alloy construction is used for all sizes.
Beware of cheaper imitations.

   1.75" x 6"..........    $45 postpaid in the USA

   4" x 13" ............    $140 postpaid in the USA

   5" x 16" ............    $185 postpaid in the USA


All sizes are overall sizes.
These smooth spun toroids permit the sparks to glide over the toroid
surface, and longer sparks can be obtained for a given toroid
diameter compared with corregated ducting toroids.

Spun toroids can be seen at my webpage at:

   http://hometown.aol-dot-com/futuret/page1.html

I've also added some photos of the spinning process and tooling
at this webpage:

   http://hometown.aol-dot-com/syncron99/tube1.html

Payment by PayPal (FutureT-at-aol-dot-com), MO, or check.  I will ship
within a week or two (or less) after receiving payment.

John Freau
49 Thiem Ave
Rochelle Pk,  NJ   07662
USA

Metal spinning is a relatively obscure labor-intensive skilled craft used for
shaping round hollow metal objects.  It is used primarily for low production
runs and for making specialty items.  It requires the use of specialized
equipment.  The spinning of a metal toroid involves 16 main steps:

1) rough cutting of the blank disc
2) trimming the disc
3) drilling the center hole
4) spinning the center area (the well) of the half-shell
5) spinning the outer curve using a different form-tool
6) trimming the edge
7) sanding the edge
8) rough cutting of the blank disc for the second half-shell
9) trimming the disc
10) drilling the center hole
11) spinning the center well area
12) spinning the outer curve on a separate form
13) forming a shallow lip on the edge
14) shrinking the edge of the first half-shell if needed for a precise fit
15) attaching the two toroid half-shells to create a complete toroid
16) metal finishing operations as needed