Re: Demonstrating... on a Professional Baseball Field?
 

If you really want to go with PVC, I guess that's ok. Only thing is that it's not rated for compressed air, and has had... shattering consequences before. Maybe try to go ABS? I dunno.

Re: Demonstrating... on a Professional Baseball Field?
 

We had two teams recently do this at a Trenton Thunder game in July, teams 1089 and 484. It was a great experience for the teams and the spectators before the game. The teams pushed their robots via carts on the track that goes in front of the dugout and the backstop, turned around, and went back to where they started. They weren't allowed to go on the playing surface. The did run their robots on the carts, essentially using their LOGO Motion arms to wave at the crowd. I don't believe they ran the robots because of the fear for dirt getting in everything! I think time was a factor too.

All in all, great stuff! The Trenton Thunder representatives hope to have them back the following year.

Re: Demonstrating... on a Professional Baseball Field?
 

If you have the resources go metal not only does it look cooler it's also safer. If you can put it on a turret that's bonus points. There are a bunch of threads talking about the different approaches for tee shirt launchers I would do a search for them and read up on some of the discussions if you haven't already and go from there if you have specific questions left just ask. And yes it seems like you could make these part work for a cannon the only thing left missing is a good solenoid. Be safe and do the research; it makes it a lot more fun when your launching stuff with your cannon.