IMHO, you have just described a new kind of air rifle with a lot of potential. I will think about this for a while! John Ferrell 6241 Phillippi Rd Julian NC 27283 Phone: (336)685-9606 Dixie Competition Products NSRCA 479 AMA 4190 W8CCW "My Competition is Not My Enemy" ----- Original Message ----- From: "Benjamin Bromilow" To: Sent: Tuesday, August 27, 2002 2:47 PM Subject: [OT] Re: [EE]: The joys of electronics > Similar but different...... > At school the physics teacher was showing that in a vacuum a feather and a > ball bearing fall at the same rate... So he bought a big glass tube with a > feather and a ball bearing in it. The ends where sealed (though one had a > nipple on it to attach to the vacuum pump). > So he slowly evacuated the glass tube (sadly not the classroom at the same > time) and lifted the tube in the air. The ball bearing and the feather fell > at the same time. The only problem was that the ball bearing fell into the > nipple blocking it off. The vacuum pump went into overload so he placed the > tube on the desk and camly switched off the pump (rather than slowly turning > down the vacuum). The inward gush of air blew the ball bearing all the way > along the tube, straight through the glass end plate, across the classroom > and embeded itself in the wall. Luckily no one was in the way............ > It took him a while to live that one down..... > > Ben > ----- Original Message ----- > From: > To: > Sent: Tuesday, August 27, 2002 3:31 PM > Subject: Re: [EE]: The joys of electronics > > > > We built a new air handler for a large office building. The air handler > > had a 200 HP fan motor, which delivered 80,000 CFM at high pressure (5" > > static). I got involved when we had to install a variable frequency drive > > to run the 200 HP motor, and interlock it with the HVAC controls. > > > > Now this was one of the bigger air handlers the contractor had built. > > Picture this, an airtight box, maybe 50 feet long, with a fan at one end > > sucking air out of the box, various filters and cooling coils inside, and > > a big wall of dampers at the other end. The dampers selected between > > outside air and return air, and the controls picked whichever one used the > > least energy to cool. > > > > Now one or the other damper *must* be open at all times, and one of my > > jobs was to build the interlock that made this happen. My stuff worked > > fine, but the contractor put tiny little motors on the dampers. I was > > *inside* the air handler when the inevitable occurred. The 200 HP fan > > kicked on, and both dampers remained closed. The walls began buckling, > > and the whole wall of dampers began to move toward me with a noise like a > > bulldozer was coming through them. . I had to hit the door (which opened > > OUT) with my shoulder a few times to get out of there alive. I ran is > > slow motion like one of those dream sequences in the movies to slam the > > panic switch on the motor controls and shut the whole system down. > > > > > > -- Lawrence Lile > > > > -- > > http://www.piclist.com hint: The PICList is archived three different > > ways. See http://www.piclist.com/#archives for details. > > > > > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body