Need ideas for an air cannon to be attached to a robot

[djbutter22]

Our high school robotics team is building a project for a competition. One of the requirements is to have the robot "kick" a soccer ball across the floor. It needs to actually lift it off the ground to clear a hurdle. I was thinking that an air powered device would be unique. I just need some ideas to put it in motion. The trigger system will need to be controlled via our radio control system. Any suggestions will be greatly appreciated.

[McCoytheGreater]

Is this for the BEST Robotics competition?

[djbutter22]

umm I'm not sure what the comp is called.

[POLAND_SPUD]

well it doesn't seem very complicated... get a sprinkler valve (not modded but with the solenoid on) and some PVC pipe and uhmm that's it

[djbutter22]

Ok Well that sounds easy enough! Its complicated to us because it will be our first attempt at pneumatics.

[jimmy101]

It sounds like it's for the FIRST competition.

The tricky part is that the gun will need a way to suck the soccer balls into it's barrel, or a mechanism to grab a ball and drop it into a breach. And, you have to be able to get the ball to the muzzle or loader in the first place (the balls are just rolling around on the floor).

Assuming you can get the ball into the barrel I would go with a piston type ram for the launcher. A pneumatic setup will require pretty massive amounts of air for a barrel that fat and the ball probably won't be able to seal the barrel very well (since that would make it much more difficult to load.)

A mechanical type launcher might make more sense. Perhaps a surgical tubing type slingshot setup.

[POLAND_SPUD]

@jimmy
the amount of air/co2 needed will be a limiting factor but it seems doable I guess... you could use an injector to suck the footballs in the barrel

as strange as it sound this will probably make a couple of things easier

[jrrdw]

You need a swinging leg on a 4 wheeled chassis. A pneumatic cannon don't kick thing's for one, and even though it would be neat it's going to need compressed air system/loading system/firing system all of witch will be a major undertaking for beginner robotics.

[POLAND_SPUD]

@jrrdw
is it stated in the rules that it can't be fired but kicked ??

doing it with an air cannon seems much simpler form my point of view... one valve to suck the footballs in, one to fire them...
plus two servos or step motors for controlling the turret

the main valve doesn' event have to be very efficient

[jrrdw]

One of the requirements is to have the robot "kick" a soccer ball across the floor.

Yup.

[djbutter22]

wow thanks for all of the replies so quickly! I will read the rules completely so I know exactly what I can and can't do. After that, I'll come back on here with my idea. We have a metal "foot" that is powered by surgical tubing but it doesn't really lft the ball.

[POLAND_SPUD]

well if it can't be fired from a gun then I guess that using pneumatics isn't the best idea...
you'd have to find a way to vary the speed of the 'foot'... and the most straight-forward way to achieve this would require you to get a proportional valve, which are quite expensive

[jrrdw]

Naaaa, use a electric motor 12v DC, windshield wiper motor out of a junk car (the older the easier to get to) the switch wire harness and everything in between. A quick on and off it will make 1 revolution and they are strong so with a 1 1/2 foot long leg the leverage will be nice.

Build a scoop on the front with the kicker lined up in the middle and BAM! Out of the park .

A car battery to run it so no power problems. RC servos controlling everything so it's fully remote control....easy.

Wow, I just built your robot in my head.

[DR]

Just follow the pictures- Pretty much self-explanatory

[POLAND_SPUD]

nice
but in what way is it 'kicking' not 'firing' ?

well I just wish they had been a bit more specific about the rules... what does 'kicked' mean ? what id didn't act directly but instead acted on a light weight piston that in turn would fire the football out of the barrel ??

@djbutter22
it seems it would be a good idea to contact them and ask them what they mean by 'kicked', as it seems that no one knows whether it's literal or metaphorical