another tennis ball launcher project..

Hey there,

I am Matt and I am new to the forum. I have recently bought a mega2560 and a UNO that I have used on a recent school project and now have the bug to create something at home. I have looked at a lot of the previous dog ball launching designs and have not found any that I am quite in love with just yet. I was thinking about using a pneumatic valve to shoot the tennis ball out versus some type of motor. Has anyone seen this done before? I was thinking about using some old paintball CO2 tanks and putting them to good use.

My goal is to at least 40-50 feet out of the shot and 75+ feet would be exceptional. (My border collie likes to run). Money is not really an object but I would like it to be challenging and fun. This project would be just in my spare time. I am looking to have some fun and expand my knowledge at the same time so I am setting my goals high.

Extending on the project, when I was completed with the launching mechanism I would like to mount it on some large type of RC car as a second phase. I have no experience with programming RC cars at the moment or what a common chassis that is used for arduino projects. My bonus objectives would be to have the car autonomously guide itself or store a route to a spot in the yard and shoot a few tennis balls(give the dog something to do when I am gone). I am not afraid to compromise. I am crossing into a few different disciplines but I have a background in software and am looking into getting some input and ideas from the community. I have a parallax sonar, ls20031 gps, mega, uno, lsm303, sd card shield, and lcd display at my disposal now from my previous project and have experience with these peripherals.

Feel free to shoot down any ideas, add any, and just give general feedback.

Thanks, Matt

Until you get to the car being autonomous, I don't see how any of these involve any electronic development or anything involving Arduino. I would have thought that a gas propelled tennis ball launcher was a very expensive solution in terms of money and resources per shot unless you already have an unlimited supply of compressed gas and are willing to carry it around with you - a motorised launcher would be far cheaper to operate. This could either be an inertial flywheel system, or a spring/winder system. (The flywheel solution seems easier to get working reliably and seems to be the more popular approach.)

Making an autonomous vehicle is a complete different and much harder problem. An intermediate step would be to use a camera on or off the vehicle to see where it is, and then use remote control via the internet to control it. That's a realistic Arduino problem. Making the vehicle truly autonomous is much, much harder and will probably require a real computer and not just an Arduino microcontroller. I wonder whether the dog would be interested in playing with an automatic ball thrower - I think you may find the enjoyment comes from playing with [u]you[/u], not the inanimate object you throw.

The point of the arduino is to control the launching mechanism.There are plenty of tennis ball style projects that use an arduino but I did not like the launching mechanism so that's why I asked about operating using the compressed gas. It really was just a project idea so I could have some fun building some sort of project. It doesn't ever have to be used. I am aware the arduino will not he used for any image processing as I was not going to use an arduino for image processing. That was just me wanting to extend the project in to future and i was asking if anyone had any experience with RC cars and arduinos..Thanks

smatty: The point of the arduino is to control the launching mechanism.

I still haven't seen where an electronic control would be involved.

Are you thinking of using compressed gas, or compressed air? I had a compressed air launcher half made when it was a casualty of some life chaos. This was probably almost ten years ago so I expect the technology has matured since then. It was a viable project then, and I expect it could be viable now. The one we were building used a modified sprinkler valve as the trigger mechanism. Hooking that up to an Arduino could be a decent project.

The Arduino is a bit of overkill unless you wanted to add some interesting trigger logic. Maybe a dog detector and a time of day inhibitor so it only launches if the dog walks by between 10:00 am and 3:00 pm or something? Or have it play 1812 Overture and fire the "cannon" at the end?

If you want to make loud noises, get dangerous, shoot a tennis ball 200+ feet, and have access to a typical oxy-acetylene torch set, try combining those in a METAL launch tube.

I pull mine out about every 5 years or so on the 4th of July...