Re: metal spinning success

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

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <teslalist-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:

 > Original poster: "colin.heath4 by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <colin.heath4-at-ntlworld-dot-com>
 >
 > hi all,
 >          iv just started metal spinning and have put my first attempt on my
 > web page. soon i hope to be doing toroids with more practice although its a
 > lot more complex than turning a half sphere
 > the pics at
 >
 > www.geocities-dot-com/colinheath2002/metalspinning.html

Why the hole in the center? It's easy (after some experience...) to fix
the material by pressure only and make complete half spheres.
Take a look at my metal spinning page:

http://www.coe.ufrj.br/~acmq/spinning

I have used this method to make spheres and rounded disks with up to
~15 cm of diameter. Presently, after getting experience with aluminum,
I only use copper, or better, brass. The half balls can then be soldered
instead of glued. To solder, I first apply some solder to the internal
edges of the half balls, and then mount the ball in the lathe, pressed
between wood blocks. I turn the lathe slowly while applying a heavy
soldering iron to the joint until the solder starts to leak. Some
polishing, and a perfect sphere is obtained.

Antonio Carlos M. de Queiroz