Something kind of like a cross between the Lego technic launcher part, and a Nerf gun. I always thought it was cool to have a robot with the capacity to shoot something…
VEX tanks!
anyhow, something that was actually directly compatable with the Vex system would be a lot easier to use than just mounting an actual nerf gun to the robot and devising a mechanical “finger” to activate the trigger. Something that you could “fire” directly from the controller…
I would not use a nerf gun or any sort of gun that requires a mechanical interface to shoot. I hooked up a gas airsoft pistol to a vex chassis and a servo that pulled the trigger. The design was ok but it was prone to not shooting if the standoff didn’t line up right.
The best type of gun that you can use is a cheap electric airsoft gun, all you have to do is open it up and solder a relay or mosfet where the trigger switch was. Then all you have to do is apply power to the relay or mosfet and the gun will start to fire.
Any simple gun will do, a good canidate would be the mini clear mp5 type guns they have at walmart. Obviously you don’t want to play airsoft with them but for a fun shooting robot $15 to $20 isn’t going to break the bank! Plus with the electronic firing system the gun will always fire unless you run out of battery’s, gun failure, or there is no ammo left.
This is what I am talking about however whether or not they used a mechanical firing mechanism or electronic is unknown as I don’t have enough bandwidth to watch the videos at the moment.
Now if you want to go OVERBOARD you can do what this guy did and build a full pneumatic cannon setup compressor, valve, tank ect… This however is expensive compared to the airsoft gun.
https://vexforum.com/gallery/files/4/1/3/1/pict0201.jpg
speaking of mounting a nerf gun to a vex robot…
this actually worked pretty well. it loaded and fired pretty well, until the duct tape i used to hold some of it together started coming loose, but then i took it apart to build something else.
you could try building a spring loaded mechanism to shoot things, or a flywheel/spinning wheel kind of thing.
Tho it seems like an air soft gun is the easiest option.
Good luck with whatever tank thing you come up with
One of our employees here at IFI (Will Beene) started out with an idea similar to yours actually. And then quickly figured out that airsoft just wasn’t enough:
Of course this is the extreme when it comes to “VEX Tanks”, totalling over $1000 to build.