Check out our cannon bot!
 

http://www.vandenrobotics.org


then click the camera icon and you can see pics and movies of it!

:)

Re: Check out our cannon bot!
 

cool. the sprinkler valve... did you just use 12vDC? most sprinkler valves are 24VAC but ive read they still work on DC sumhow...

Re: Check out our cannon bot!
 

:ahh: Very nice! We've got a compact tennis ball cannon mounted on (of all things) a Vex platform here. It's quite fun to shoot tennis balls down two buildings worth of hallways. The sprinkler valves come in quite handy and although they are spec'ed for 24V AC, they trigger perfectly fine with 3 9V batteries in series, perhaps through a spike relay for remote firing.

Re: Check out our cannon bot!
 

Just last night, team 1147 had the opportunity to shoot their Robot Mounted T-Shirt Cannon during a "TV time out" at the Sacramento Kings vs. New Orleans Hornets NBA game. Our first shot landed two shirts in the upper deck of ARCO Arena. A feat that their mascot Slamson is unable to do even with only one shirt. :D
We will post a video as soon as we can get it edited (a long period of "out of focus" needs to be removed).
We use the same Rain Bird sprinkler valve set up. We trigger it off 12vdc through a Spike.

Re: Check out our cannon bot!
 

My team is interested in making a cannon to put on the arm of our '05 bot. Anyone have a drawing of how it is put together and what parts are needed? Do we need to add an extra compressor (or two) on the robot to get the pressure and volume of air needed?

Thanks!

Re: Check out our cannon bot!
 

look up potato gun or sumthing on google. PLENTY of tutorials and step by step instructions.
oh and unless you are decently educated with highpresure air, this can be VERY dangerous. dont try sumtihng unless ur sure it works

Re: Check out our cannon bot!
 

Heres a great thread: http://www.chiefdelphi.com/forums/sh...t=shirt+cannon

Thats where we got our idea. Basically, we followed their lead ( with thanks to bilbo) but used two KOP compressors for a faster fill rate. We now have a transducer on it so you can "dial the pressure" from the OI.




Heres a video of one of it's first decent shots.
http://media.putfile.com/T-Shirt-Cannon

Re: Check out our cannon bot!
 

never really seen one in real life so i dunno so, wahts that clanking noise as it fires? valve? oh btw what kind of tanks are you guys using?

Re: Check out our cannon bot!
 

As a general warning, be EXTREMELY careful if you are using PVC for pressurized air storage. Even if it is rated to pressure much higher than what you will be using, it can be dangerous. It is designed for incompressible liquids that don't store much elastic energy. Compressible gases, on the other hand, store tremendous amounts of energy and can cause violent explosions. It is for this reason that PVC manufacturers explicitly state that it is not to be used with compressed air.

If you are going to use PVC for an air cannon, make sure it is pressure rated (it will say so right on the pipe) and make sure you properly cement all connections. Also, DO NOT use it outdoors in cold weather - the plastic becomes very brittle and is more likely to fail.

Re: Check out our cannon bot!
 

I can confirm that sprinlker valves will work off of 24VDC. For PVC, don't put any more than maybe 25 psi in it without gluing all the pieces, and when you glue them, let it dry for a long time to make sure it is fully cured.

But air cannons are very fun projects. You can easily make a quite nice fog horn too.

One thing I did while messing around with this stuff was to drill out a PVC end cap and thread in a quick release fitting for the air hose. It worked fine, and was very easy to do. Just to let you know in case you were wondering how to hook up the air, that is one way.

Re: Check out our cannon bot!
 

As promised, here is the video from Sunday night at the Sacramento Kings game.
Please forgive the quality, I have not yet had a chance to clean it up. I will once I get the correct software running.
Team 1147 at Arco In the background you will hear the team being announced just after the shirts land in the upper deck!

Re: Check out our cannon bot!
 

can anyone confirm for 12 or 14V DC? why tho? i dont understand why.... kinda like how a light bulb works i guess? and anyone explain the sound i asked about 4 posts down?

Re: Check out our cannon bot!
 

Good place to start is wikipedia - search for potato cannon. In there, there is a link to here: http://www1.iwvisp.com/thehalls/ggdt/ where you can get software to calculate theoretical velocities and stuff. He also has a page showing how to modify a sprinkler valve for rapid discharge (for manual firing), and pages discussing different designs of spud guns and paintball guns.

Make sure you read various safety warnings about PVC guns! Use only pressure-rated pipe, prep the pipe and use primer, allow the cement to cure for at least 24 hours and don't use them in hot or cold weather.

You could probably modify a sprinkler for pneumatic opening, then use a 12 volt air valve from one of the old pneumatics kits as the trigger instead of the solenoid.

Our latest toy is a 20 lb. propane tank connected to a 1 inch pipe. Overkill, yes, but shooting a carrot at something solid makes instant carrot juice. More like orange fog.

Re: Check out our cannon bot!
 

And here I though I was the only mentor that had more fun with these "toys" than our students do! Silly me! :D

Re: Check out our cannon bot!
 

My 16 year old does the building, I just buy the goodies.

My favorite is a 2 liter soda bottle with a 1/4 to 5/16 inch (or so) hole in the cap. About a 6 to 7 second spritz of propane from a torch, put the cap back on, put it on some sort of guide rail and light it. WHOOSH. It ignites and the exhaust goes sonic, so watch your ears and don't get burned by the hot exhaust. It'll send a bottle quite aways. You have to squeeze the bottle a few times to purge between firings. The bottles start to deform after several launches.