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

Re: Toroid made easy



Original poster: Finn Hammer <f-h@xxxx>



Tesla list wrote:

Original poster: gary350@xxxxxxxxxxxxx
I cut 2 pieces of .040" flat steel into a donut shape. Donut is 20" outside diameter with a 6" diameter hole. Metal plates are welded together along the outside and inside edge only. A very small pipe fitting is welded to the surface of 1 sheet of metal near the center.


^^^^^^^^^^^^^^^^^^
Except you just cut out the center.....
I would suggest a long pipe fitting, unless the pressure hose should catch fire....

A 5 lb. bag of charcoal is ignited and given enough time to turn the 2 metal plates red hot. Air is slowly blown into the fitting and the red hot metal is blown up like a balloon. The flat metal will blow up into a toroid shape it is sorta like blowing up a car tire innertube.

Great speculation. And it does work well with elastic materials, like rubber, where tension gets distributed evenly in the material.

Steel is different, though.
When you apply a bending force to it, it is elastic to a point, then it turns plastic. It does not aquire permanent deformation, unles it is stressed beyond the point of plasticity.

Now this goes for cold steel. Red hot steel is always plastic, and the plasticity is dependant on temperature. Without elasticity, deformation takes place where the material is hottest. You`d have to get the temperature of the metal very even allover the workpiece. I find it hard to beleive you can du that to a 2-layer sandwich of thin metal sheet in a charcoal fire.

But you`d have to keep the metal on, under? in? the charcoal while blowing it up, to keep it hot. What if it blows a hole, or a weld breaks? You`d have pressurized air from a ressouar allover the hot charcoal, blowing that coal everywhere including in your face.
A lot of danger here.

With 30 years of metal working experience under my belt, I have to say this:
Making toroids this way?  I`d have to see it before I beleive it.
I don`t think that anybody with much metal working experience would bother to try, so, untill I see evidence that this method has actuallt been tested, I warn everybody against trying to do it.

But I could be wrong, of course, so: will you pls. supply a picture of the finished product to the list.

snip

Cheers, Finn Hammer


Gary Weaver