Re: Another improved propeller gap

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

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 15:39 01/02/03 -0700, you wrote:


>I've got more of those rings than I could shake a stick at - would be 
>interested to hear of your results.
>
>Got a nasty suspicion that the aluminium will actually deform in time 
>without a disc either end.

I fired it up today. Without a tacho I could only estimate from the sound 
of the motor (you get a beat with the line frequency at 3000, 6000, 9000 
etc) and I reckon when I dimed the variac it hit almost 20000. I kept it 
there for about a minute to give it a chance to blow if it was going to. 
The rotor was totally fine but it did vibrate somewhat. The motor 
(universal type from a mini vacuum cleaner) now runs pretty rough and I 
think I probably wrecked the bearings. It was never meant to spin that 
fast. I don't really care- it still runs fast enough and the noise of the 
TC should drown out its squeals of protest :D

I noticed your suggestions of Kevlar fabric, sounds very trick, but I 
suspect a couple of bits of steel will do just as well.

Steve C.