Check out our cannon bot!

[Salik Syed]

http://www.vandenrobotics.org


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

[greencactus3]

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

[ZZII 527]

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.

[billbo911]

Originally Posted by ZZII 527

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.

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.
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.

[coastertux]

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!

[greencactus3]

Originally Posted by coastertux

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!

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

[Andrew Blair]

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

[greencactus3]

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?

[ZZII 527]

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.

[sanddrag]

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.

[billbo911]

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!

[greencactus3]

Originally Posted by sanddrag

I can confirm that sprinlker valves will work off of 24VDC.

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?

[Eric Scheuing]

When did you make this?

[billbo911]

Originally Posted by Eric Scheuing

When did you make this?

We built the t-shirt launcher over the summer. It is mounted on our 2005 'bot.
I guess we must have had a little premonition about the need to learn about launching stuff!!

[Doug G]

Originally Posted by Eric Scheuing

When did you make this?

Ok so we figured out the game like back in Sept and built our robot early - so when do the competitions start? - we're tired of waiting already!!

You can see it shooting a ball at our website...