Re: More Tuning/Debugging

To: tesla-at-pupman-dot-com
Subject: Re: More Tuning/Debugging
From: Jim Fosse <jim.fosse-at-bdt-dot-com>
Date: Wed, 11 Sep 1996 04:25:23 GMT
Chuck:
> > The stationary gap is suffering at this point.  I built
> >it with the gaps "close" to .028" each but now they vary from .014" to
> >.041".  I used 3" lengths of 1.5" O.D. copper couplings not tube.  They
> >have apparently stress relieved themselves with the heat and now have a
> >changed shape.  They were both bolted and epoxied into position in the
> >PVC tube.  I'm in the process of starting a new stationa gap system with
> >a vacuum cleaner motor.  More later, thanks for the feedback.

Chuck, did you use steel or brass bolts?
> >
Jim:
> I find this interesting. I built my stationary gap with 1" Cu tube
> sections bolted but not epoxied in place. It has always been
> blown/cooled. I gap it to 0.030" and then, later, find that they have
> moved;) Some are shorted, some as much as 0.060" apart. I figured that
> this was due to not epoxying them in place. It has happened enough
> times that I do not beleive it is stress relief any more.
Steel here.
> 
Ed:
>I built my cylindrical static gap with 1.5" dia copper pipe.  I used brass
>screws and nuts to hold them in place.  Each pipe is also epoxied to the
>large pvc pipe section they are mounted in.  The gaps are set to about .030".
> A muffin fan is mounted on the top with legs on the bottom to hold it about
>2.0" up off the floor.  The copper sections have been hot enough to turn the
>surface blue - but no distortion yet.  All the gaps seem to be holding as
>originally set.  I originally built two of these and one has several hours of
>run time and still works great.
>
brass here.
>

Hum,
	I'm using 1" Cu pipe with 3/8" steel bolts. I wonder if it's
the different temperature coefficient between steel and copper that is
causing my gap to walk?


	jim


The phrase "Cold enough to freeze the balls off a Brass Monkey"
originated with the (sailing) war ships going around the "cape". Only
down there did it got cold enough that the balls fell off the Brass
Monkey. i.e. the Cannon Balls shrunk in diameter and the Brass
Monkey's rails shrunk in diameter enough that the balls no longer sat
on top but fell through. The Brass Monkey was a set of parallel brass
rails that were used to roll the balls from their storage place to
each cannon rather than carry them.

Enough temperature coefficient trivia.