Network Learning Project

I have successfully assembled and tested my launcher.  As I explained in my previous post I had to redesign it since I couldn't get the correct size PVC pipe.  The launcher is made up of an air chamber, valve, barrel, and a piston.  When the valve is opened, compressed air rushes out which pushes the piston forward.  The piston quickly accelerates down the barrel and rams into the tennis ball which is help at the very end. The piston is held in the barrel by a length of thin rope so after it hits the ball it stays inside the barrel.

Here is a video of a test in slow motion.

As you can see in the video the piston impacts the ball and it shoots out.  The piston is made out of a short section of dowel.  The dowel has two rings of electrical tape wrapped around it and greased up to act as an air seal in the barrel.  This was an old trick I learned from some internet sources.

Overall this project meet some of my objectives and not others.  It is simple to use and effectively throws the tennis ball, it was also very cheap to build after I redesigned it.  Still, it has not meet my range expectations yet.  In this test I was operating the ram at 160psi (the limit of my bike pump).  I have tested the air chamber up to 300psi and know that it can safely function at that pressure.  The next step will be to test the ram at higher pressures to see if the range can be increased.

But for now my coverage of this project will have to end.  The overall goal was to use the internet to learn something new and I think I have achieved that.  I utilized many forums and videos in the making of this launcher and while it isn't perfect, I know that there are further resources out there that can help me refine it.