[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] Tubing



Another possibility is to do a Google search for 'mandrel bent elbows' and get four of these bent 90 degrees, cut them off at the tangent points, and weld them into a toroid. It works great and is cheaper than a new spun toroid. Check different companies for largest size, price, etc. You can also leave some of the straight sections on and have a rectangular toroid.

---Carl






Jay,

see:

http://www.harborfreight.com/tubing-roller-99736.html

Price has gone up significantly since I looked at it last. Friend of mine bought one, and it's a decent unit. Making good rings is harder than it looks, though.

The harder part is actually finding thinwall aluminum tubing at a decent price in long lengths. Last I checked, it was quite expensive, and shipping is a bear, unless you can find it surplus locally somehow. If you want a 5 foot toroid, you need a 16+ foot piece to start with, as the bender leaves short straight segments at each end of the ring that you have to cut off.

I was going to try using some very large size semirigid coax cable, less its outer insulating sheath. I found some of this material at a hamfest that's nearly 1.125" - 1.25" OD, for a very decent price. The shield is heavy continuous corrugated copper, not braided, and not foil. I'd just ignore the center conductor. Problem is that it is significantly heavier per foot than the AL tubing would be, but it would look extremely cool. Looks like the legs of the squid robots in "The Matrix".

There is also another kind of semirigid coax that's about 5/8" OD. I've always seen it without an external insulating jacket. For a ring toroid up to two or three feet or so in diameter, it might work OK. Also turns up at hamfests occasionally.

Unfortunately, with copper prices being so high, not much wire of any kind has shown up at recent fests.

Don't forget to check the TCML archives for the multisphere toroid alternative. A couple of years ago, there was a lot of discussion of using 4, 6, 8, or more stainless steel gazing balls in a planar circular array to approximate a toroid. These can sometimes be found on eBay at a decent price. They also look cool, and do provide a reasonable alternative to a big spun AL toroid.

Dave

On 4/21/2012 11:10 PM, jhowson4@xxxxxxxxxxx wrote:
Thanks Dave I will look into it.  :)

John "Jay" Howson IV

----- Reply message -----
From: "David Speck"<Dave@xxxxxxxxxxxxxxxx>
To: "Tesla Coil Mailing List"<tesla@xxxxxxxxxx>
Subject: [TCML] Tubing
Date: Sat, Apr 21, 2012 8:22 pm


Jay,

Harbor Freight has a very nice tubing bender that does the job. Under $100 when it goes on sale, or when you find one of their 20% off coupons in a magazine.

Dave

On 4/21/2012 4:52 PM, jhowson4@xxxxxxxxxxx wrote:
Hello all,

I was curious to know,
How do you guys who make the tubing based toroids bend the tubes into such nice circles of the various diameters?

Thanks,
John "Jay" Howson IV
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla