Originally Posted by Andrew Schuetze

This was indeed prototype 0.1. I used 8 KOP tanks in four parrallel circuits. I.e. two tanks in series feeding into a manifold with four inlets. The manifold was all 0.5" black pipe tees. I then used couplings to enlarge the opening to the 1.0" diameter for the sprinkler value. Not nearly enough air flow was generated to launch the tee shirt out of the 3.0" diameter barrel.

Originally Posted by Billfred

I get the basic concept, but what would work for the pin? It'd have to be something strong enough to handle the force of the cylinder, yet also be able to be yanked out of place (or so I think).

Originally Posted by KenWittlief

Im having a hard time with some of the ideas being presented of ways to make a PVC tank less dangerous by wrapping it with nets or tape or wire

that seems like a seat of the pants kinda thing to do. You would have to test the end product many times to see whether it contained all the little pieces, or whether it made things worse. You would have to repeatedly blow up PVC tanks in a controlled environment, and find a way to measure the energy of the resulting fragments. (Sound like a job for the MythBusters!)

And dont forget the concussion if it blows in a small area. It doesnt take much of a bang to permanently destroy your hearing.

This reminds me of people who put an X of tape across their windows or sheets of plywood, when a cat 5 hurricane is coming. When they return their house is completely gone!

Originally Posted by Andrew Schuetze

When I get a bit more time, I'll add links to the various threads on C.D. on this topic.

My question is how / where does one get a definitive answer as to the pneumatic pressure rating of schedule 40 PVC? I was intrigued by the team fusion air canon last year and then decided to add one to our 2005 robot this August. I'll post a picture of the prototype mounted on my classroom workbench. It works okay. Based upon three weeks of development, what I perceive to be limiting the performance is the restriction of air flow from the storage tank via the 0.5 inch fitting. Everything else is the same 1" diameter as the sprinkler valve and then expands to the 3" diameter at the back of the muzzle.
I've seen about three cannon systems which are using PVC pipe as the pressurized air storage system here on C.D. People have commented that PVC pressure ratings are for water systems and in fact the fine print at the store indicates use for water only.

My fear is that a bump into a doorway or drop on the floor may start a crack in the PVC pipe and eventual lead to catastrophic failure.

How do I know if I am being overly cautious or just being prudent?

APS


Toltech prototype

Originally Posted by RyanN

Just a suggestion, if you get a sprinkler valve that is rated at 24 volts, don't run it in series with a spike. The spike leaks enough current to keep the valve on after releasing your firing button, and it will not work right with only 12 volts. We use 3 9V batteries in series going through a relay connected to a spike and it works well for us.