My daughter decided the potato cannon stand needed a bit of color. Here are the results:
Looks a bit to me like camouflage from the Avatar movie, but I’m not a pre-teen.
Also decided to RTV over the electrical connection on the potato cannon. This will reduce the chance of someone getting shocked. Not very likely, but better safe than sorry.
Also started work on the pneumatic cannon. Decided to keep it small so that I can finish it in time. The air chamber will be made up of 3″ PVC. I can then use a “T” connector to a ball valve and 1.5″ PVC for the barrel.
I started by gluing a female threaded connector to the barrel. This allows me to separate the barrel if I need to clean out an obstruction.
To this I’ll connect a male threaded connector, and then use various adapters to get me to a threaded nipple. This will be needed to connect to the ball value. Here’s how the parts will lay out, with the barrel on the right.
I’ll use a similar set of adapters on the other end of the ball valve. This will connect me to the “T” connector, to which I’ll attach 3″ PVC in order to form the tank. Here’s some snaps part way through the gluing process:
And yes I’m remembering to tape all of the metal to metal connections.
Note the air tank section above only has one cap. This is because I have special plans for the other cap:
The top component is an air gauge so I can monitor pressure in the tank. The bottom component is a standard air valve for an automobile tire. Usually these just pop into place, but I decided to go with one that is threaded so I can use a nut to lock the connection point firmly. A bit of lock tight on the threads, and hopefully I’ll get an air tight seal. One of the problems with this build is that any air leaks pretty much requires that you throw half the unit away and start over. Want to do it right the first time.
So here’s where we are at so far:
Give it the day to dry and I’ll be able to check for leaks and do a test firing this evening. Total build time was just over an hour. Soooo much easier than a 10′ catapult!