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Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
Apologies if this has been discussed to death previously.
Anyone have creative ideas for toploads? Toroids, spheres, etc. I'm really not a fan of the dryer duct toroids, but I have yet to find much in the way of toroidal or spherical commodity objects. Has anyone looked into a run of stamped aluminum toroids rather than the typical spun ones? How to spheres compare to toroids from a functional standpoint? They're a bit easier to come by and I like the look.
Registered Member #1225
Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253
Im fairly certain that you would get the same spark length from a sphere and toroid, but different shapes have different E-fields which can make breakout occur in different directions. Toroids tend to break out sideways, and spheres tend to break out upward.
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
James wrote ...
.Has anyone looked into a run of stamped aluminum toroids rather than the typical spun ones? .
Depends on the size of toroid you require. Smaller toroids would only require a small press (screw thread, not hydraulic), a couple of hardwood dies (male and female), and a means of annealling the aluminium.
The two halves would then require welding together, and the welds ground down, and subsequent polishing but the welding could be 'outsourced'.
You'd press them in stages, stopping when you feel the aluminium work hardening (increased resistance) to re-anneal.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
You can sometimes find stainless steel spheres in Home Depot and the like, in the garden section. I think they're called "gazing balls".
A quick look round Ikea, or your country's equivalent, is sure to turn up some suitable stainless steel bowls. Two of these can be fixed together with aluminium tape to make a vaguely topload-shaped object. (That's when you know you're obsessed with Tesla coils- when you go to Ikea, you see toploads.) This used to be my favourite method, plus some pieces of metal lampshade "adjusted" with a mallet.
John Freau sells spun and polished toroids at reasonable prices, considering the amount of work involved. I have three of various sizes.
Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
In the same theme, there are many cake or Jello molds,that, buying two of them and bolting (or welding) them together will yield a toroid. In the "Kitchen" section of many stores are various substitutions that may work well. I did find one that was a "half toroid" at WallMart (aluminum), ground the lip off of it and it appeared fairly nice for a small coil.
Registered Member #72
Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659
I'm sure a lot more could be done on a small scale with cage / frame techniques. With care it could be made to look very professional, like LOD's toploads here
Registered Member #3567
Joined: Mon Jan 03 2011, 10:49PM
Location: USA, 1960s
Posts: 260
I was thinking about something a little more complex. What if you take a plastic ball, and then spray it the metal paint. If you left it like that, the metal would just burn. Then, you electroplate the thing with copper. THEN, you cover the thing in silver solder.
Registered Member #1221
Joined: Wed Jan 09 2008, 06:17PM
Location: Odense, Denmark
Posts: 196
What if you take a plastic ball, and then spray it the metal paint. If you left it like that, the metal would just burn. Then, you electroplate the thing with copper. THEN, you cover the thing in silver solder.
Would there not be a problem with the plastic ball and the relatively high temperature required to melt the silver solder ?
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