View Single Post
  #27   Spotlight this post!  
Unread 23-05-2010, 01:28
EricH's Avatar
EricH EricH is online now
New year, new team
FRC #1197 (Torbots)
Team Role: Engineer
 
Join Date: Jan 2005
Rookie Year: 2003
Location: SoCal
Posts: 19,827
EricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond repute
Re: Most Powerful FIRST Team created T-Shirt Cannon

It's how it fails that's the issue. Water, you get an incompressible (or close enough as to be easily approximated as such) fluid that, if it's under some pressure (as it might be in a sprinkler system), and it gets an outlet, it will leave in a reasonably orderly fashion, spraying out until somebody turns the water off.

Air, on the other hand, will try to all leave at once, causing further mayhem as it breaks whatever it's in further. If you have something that's rated for air, presumably it would have failure modes to safely release the air even if something breaks.

What we're concerned about is the "mayhem" as the PVC breaks. I've seen PVC that's fallen from a height of about 3.5' break (fortunately, no pressurized air inside).
__________________
Past teams:
2003-2007: FRC0330 BeachBots
2008: FRC1135 Shmoebotics
2012: FRC4046 Schroedinger's Dragons

"Rockets are tricky..."--Elon Musk