RE: [TCML] Kinraide Coil Reproduction - Near Completion. Near exhausted.

[Jeff Behary <electrotherapy@xxxxxxxxxxx>]

Phil,
First off, that sounds like a lot of fun.  A friend and I want to make a carbide cannon, only 4" in diameter...
 
I read that Bowling balls were made standard of hard rubber from 1906 to the 60s/70s.  Normally, you can tell hard rubber because its a blackish color that fades to dark dull brown over time.  Many people mistake it for bakelite - old telephone receivers, "Violet Ray" hand pieces, and other moulded items were normally this material.  If you rub it briskly with your hand, and then smell your hand - it should have a familiar "burnt rubber" smell...
 
I am guessing the least fancy ones of the past are probably hard rubber, just a typical black bowling ball...?   To confuse matters (or maybe not?), there are bowling balls manufactured under the tradename "ebonite".  I am guessing this is a name from the past, an old company, they might be of help in finding this material though....
 
The material hard rubber, vulcanite, ebonite, whatever you want to call it is a difficult one to find in general.  They sell it for friction rods, made in India still, for static experiments.  But finding a source that really has it (as opposed to advertising they have it and then calling them to find it backordered or out of stock) is difficult.  Its a neat material, similar to bakelite.  It polishes extremely glossy.  It also fractures easily, but has great electrical characteristics.  It was a material that most hobbiests couldn't afford at the turn of the century, it was then about what G10 is today (as far as desirability vs. "%^%(* that's expensive!")
 
In any case, 8" OD for coil forms would be astronomical in any material.  Bowling balls (of any kind) are looking pretty good!
 
Jeff
 
> >If anyone has an old Bowling ball, made of Ebonite or Vulcanite, no longer > needed, if you send it my > >way I will machine proper hard rubber coil forms! It would be a dream to > actually to do this, in the > >same way that getting silk covered wire to use was a dream to wind with. > But I don't know where to > >get them in South Florida. It'll be a real interesting task to turn them > on the lathe, but I am sure > >willing to have a go!> > > How old a bowling ball would this be? How do you ID one as made of > Ebonite or Vulcanite? > I purchase bowling balls at thrift stores for dirt cheap and pick them > up at the recycling yard fairly regularly (I shoot them from a cannon, and > they tend to be hard to find afterwards). I've also shot *at* several bowling > balls - which is almost as fun since you can put "english" on them by winging > them with a high-power rifle. You can spend all day launching them out in a > field, then make them roll around wherever you want until they get too small > and lumpy.. > My point is that I've got some familiarity with the construction of > bowling balls, and the ones I've come across are in two general flavors: solid > all the way through swirled/colored plastic, or cork and rubber core with a > tough outer skin. Is the Ebonite/Vulcanite different, like a solid rubber?> If I know what to look for, I'll keep an eye out and send them to you.> BTW, look at how the pro shops fixture balls to drill finger holes. > Might be useful when it comes time to machine yours down.> > > -Phil LaBudde> Center for the Advanced Study of Ballistic Improbabilities> 
_________________________________________________________________
Get thousands of games on your PC, your mobile phone, and the web with Windows®.
http://clk.atdmt.com/MRT/go/108588800/direct/01/_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla