Re: My first ARSG, or a Dangerous Design?

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

Original poster: "Barton B. Anderson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <classictesla-at-netzero-dot-com>

No, but will cause the tungsten to press into the set screw and into the 
threaded hole applying a "goodly" amount of pressure to the tungsten. There 
is no "dig into" the tungsten, but there is definitely pressure. It's nice 
for adjustments to keep the electrode "unscathed". I've used a set screw 
setup on a G10/tungsten disk for quite sometime now, and have never had a 
set screw (1/4") or electrode  (.375" x 1.25") come loose.
Just don't use screw locking adhesives (Loctite, etc.). Electrodes get hot, 
thus, set screws get hot. This heat causes adhesives to expand and begin 
stress cracks in the set screw wall. Bad things are then "predictable".

Bart

Tesla list wrote:

>Original poster: "Crow Leader by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><tesla-at-lists.symmetric-dot-net>
>
>A set screw probably won't press into tungsten and lock in place. It sounds
>likely that the collars themselves would fly off.
>
>KEN
>
>
>----- Original Message -----
>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: <tesla-at-pupman-dot-com>
>Sent: Friday, January 24, 2003 1:33 PM
>Subject: Re: My first ARSG, or a Dangerous Design?
>
>
> > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
><Esondrmn-at-aol-dot-com>
> >
> > In a message dated 1/23/03 5:56:50 PM Pacific Standard Time,
> > tesla-at-pupman-dot-com writes:
> >
> >
> > >Hi Scott, Dan, Terry B, All,
> > >
> > >OK here is some CONSTRUCTIVE criticism. IF there really is a problem of
>low
> > >coefficient of friction causing slippage, here is one way it can be
>easily
> > >cured:
> > >1) Push tungsten rod through an externally taper-threaded piece of split
> > >brass tube, so that the tube is in the middle of the rod. The tube must
>be
> > >about 0.5" longer than the width of the hub. Hole in hub should also be
> > >threaded.
> > >2) Thread tube with rod in it through hub.
> > >3) Put a locknut on each end of tube to both lock rod into tube and hold
> > >tube locked into position in hub.
> > >4) Balance and Run.
> > >5) Naturally, all plastic parts subjected to rotational stress must be
> > >inspected periodically for wear and replaced when wear is observed. This
>is
> > >true for HDPE, Nylon, Lexan, or G10.
> > >
> > >Without these modifications, even at 15,000 rpm, the tip speed of an 8"
> > >rotor is  ~524 fps. If the rod did start to slip out, it would impact the
> > >stationary electrodes before it could leave the hub. While this would
>most
> > >likely wipe out the rod, the electrodes, and the hub, it would be less
> > >dangerous than an airborne disk or tangentially-flying small electrodes.
> > >The design is very creative and hardly what I would call "makeshift".
> > >
> > >Matt D.
> >
> >
> > Another idea would be to use some locking collars on each side of the
> > flying electrode, butted up against the poly block that it is pressed
> > into.  I noticed I have some of these in my model airplane hardware
> > box.  They have set screws in them for locking and I am sure they are
> > available with different size holes in the center (to fit different
> > diameter rods).
> >
> > Ed Sonderman
> >
> >
> >
>
>
>