Paintball Assault Vehicle: Phase II

Brad's Wood Shop

Paintball Assault Vehicle: Phase II - The Cannon

Before I go any further, I feel that I must insert a disclaimer here. This thing definitely has the potential to cause serious harm or worse. In other word's, don't try this at home kids! And definitely don't assume anything you see here is scientifically proven. We've taken some good ideas from PVC guns and cannons built by others and tried to improve upon those, and what you see here is our first design. What you do with anything you see here is your own responsibility.

That said, this air operated cannon was built with maximum safety in mind. All exposed parts are either aluminum, steel, iron, or brass, all of which are rated far beyond the working pressure of the cannon; or air hose which is rated at 300 psi. This cannon was built specifically for paintball scenario games, and is used only to fire foam rockets and paintballs within the velocity restrictions dictated by event organizers.

These premises protected by....

Check out the following pictures to see how the cannon was built.

This is our first layout. In this picture, we're using a 1" plastic sprinkler valve. We quickly decided that plastic was too wimpy, and 1" was too small.

This is the chamber. The threaded plug unscrews to allow the projectile to be breech loaded. Notice the tabs welded to the chamber to secure the aluminum barrell. The galvanize had to be ground off the fitting in order to MIG. This is all to enclose the schedule 40 PVC barrell liner.

Here's the key to triggering the cannon. It's the top of the 1-1/2" brass sprinkler valve. The solenoid ports are way too small to be effective, so I drilled and tapped a 1/8" NPT hole directly through to the diaphram. We don't use the solonoid at all. The trigger mechanism is strictly mechanical (blow gun).

Here's some pictures of the assembled cannon.

Here's another pic showing the components, including the 1" plastic valve.

In this picture, you can see a 3/8" pin welded to the side of the chamber (there's one on each side). These will serve as a pivot point for a breech plug safety latch yet to be constructed.

Here's a view of the inside of the valve where the hole came through. Luckily, this particular valve had a blank casting area that was a perfect spot to drill the hole. Notice the tiny ports for the solenoid.

Here's the blow gun/hose trigger assembly.

Here's a picture of the muzzle showing the front sight and the schedule 40 PVC barrell liner.

After test firing many times, we realized we had to overcome some loading problems. First, since the breech is a "T", the loads had room to open up before entering the chamber and they wouldn't slide in. Second, when a load opened up accidentally, the paintballs would drop down the "T" and the only way to get them out was to turn the canon upside down ( would not be possible when mounted on the tank). Hmmm. What to do...

The mesh in the above pictures will not restrict airflow in the least. Problem solved! Stand by, Gary's working on an idea for perfecting the charge...

What's left to do? Testing for ideal operating pressure, designing the loads, and mounting the cannon to the tank turret of course!

Check back soon, we'll be finishing this up and taking some more pics in the coming weeks.

Update #1:

Below you can see the tube steel frame for the turret, along with the cannon mounting bracket.

Here is a picture of the bracket/roller assembly built for the rear of the turret to offset the weight of the cannon hanging over the front of the turret. Padding added to protect gunners back.

Below is a picture of the air system used to fire the cannon. It consists of two 12v compressors, reservoir, 2 solenoids (on at 90psi, off at 110psi), and a hose to pressure the cannon.

Update #2:

Although we've perfected a good paintball charge for the cannon, we were not allowed to use it. So far we've been restricted to scenario provided nerf rockets only. The cannon is quite accurate with good range using these rockets.

AH! To the scrap bins! I had ripped apart an old refrigerator and the ice maker on the door had a flat rigid stainless steel mesh that was used to support the cup under the ice/water spout. I knew I kept this junk for a reason... I formed it into a cylinder shape by hand and inserted it into the breech. I then inserted a tailpipe expander inside the mesh cylinder and expanded the mesh against the walls of the "T". Believe me, it cannot be any more perfect!