Re:[big plasma ball]+ plexiglas parameters

• To: tesla-at-pupman-dot-com
• Subject: Re:[big plasma ball]+ plexiglas parameters
• From: "ROBERT CRESSLER" <robert.cressler-at-menasha-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
• Date: Wed, 19 Apr 2000 11:49:30 -0600
• Approved: twftesla-at-uswest-dot-net
• Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

 
>>> <Tesla-at-pupman-dot-com> 04/18/00 08:52PM >>>
Original Poster: "Bill Noble" <william_b_noble-at-email.msn-dot-com> 

>as you figure, are you accounting for 15 pounds per square inch, or
>144X15=2160 pounds per square foot of pressure as you evacuate this thing?
>if you figure the surface area of your 9 ft sphere, you will see that you
>have one heck of a lot of pressure to hold off - I doubt that a PVC and
>plexi frame can do the trick - look up the size of plexi to use on a fish
>tank (30 ft of water is about an atmosphere) - figure the tank is 30 ft
>deep.  If you go to the aquarium at Monterrey (CA) you will see that the
>windows are about 4 or 5 inches thick to hold the pressure - you will need
>more than an inch of plexi (I would guess) and some really strong struts and
>good seals.   

   bill,
        good guess! my old 1960's "Handbook of Plexiglas" has a empirical
formula for determining the minimum thickness  of  Plexiglas for"circular
domes" in full vacuum applications as t=d/32
t=preforming thickness of plex
d=dome dia
108/32=3-3/8"thk!  yikes! 
I am unclear if this could be extrapolated to a full sphere,but I bet it is
in the ballpark
(probably on the light side)
Robert 

• Prev: Re: Secondary winding spacing
• Next: Re: Solid state spark length record?
• Index(es):
  • Main
  • Thread