The Can Launcher Project

Construction: Part II and Initial Testing

2007-06-24T20:22:00.000-07:00

I've measured out where the piston lands and cut a hole to allow a can to be side-loaded in the barrel. This also allows for some of the pressure to be drained out of the barrel when the piston reaches it's maximum travel, reducing wear on the cable/rubber band assembly and slightly decreasing time to reload. The top and bottom corners of the cut (top being towards launching end, bottom being towards reducing couplers) have been filed down so as to provide less of a sharp angle to snag the loosely moving piston.

This is a closeup of the loading hole:

And a shot of the entire test assembly:

Now some videos and pictures of the test! The can was launched on average around 15 feet at 70 PSI.

Construction: Part 1

2007-06-22T20:04:00.000-07:00

The following is results from the first few days of construction.

This is a 3" to 2" reducing coupler attached to a 2" to 3/4" reducing coupler. There are two eye bolts screwed into the top of the 3/4" reducing coupler, through which are threaded two rubber bands. A piece of copper welding rod is passed through the loop formed by the ends of the rubber bands, keeping the rubber bands secured in place. The rubber bands also pass through the eye formed by a small steel cable. More on that cable in the next picture.

The reducing coupler are connected to a small piece of 3/4" PVC, approximately 3" long. The steel cable is shown here linking the reducing bushings to the piston, made of air filter material wound and taped cylindrical with duct tape. The next design will probably incorporate a segment of "Fun Noodle", a foam cylinder used as a pool accessory.

The piston is loaded in the 3" diameter barrel, which is about 32" long. The reducing couplers are attached to the rear end of the barrel. The piston design is used because no PVC the diameter of an aluminum can exists. Theoretically, this design also allows for objects of any size less than 3" to be launched from the barrel. Air will fill the space behind the piston rapidly, accelerating the piston and the can on top of it. The piston reaches the end of it's tether, and due to the elastic effects of the rubber bands and gravity (we are assuming the launcher will be in a mortar configuration, a very high launch angle), the piston will return to it's starting position. This will allow for a side-loading feature to be built later.

The air tank is constructed out of remaining 3" PVC and a short segment of 3/4". A solenoid valve is installed to release the pressure accumulated in the tank and fire the launcher. A tire valve stem is installed on the end cap of the 3" PVC, to allow the tank to be filled with a portable 12V tire pump.

The final assembly for today:

Genesis

2007-06-21T12:53:00.001-07:00

The Can Launcher Project, started June 16, 2007, is a design project established to create a device that can cheaply and efficiently launch aluminum cans filled with beverage (beer, soda, etc.) to people. The project was inspired by the Beer Launching Fridge designed and constructed by John W. Cornwell, a student at Duke University (you can find his website here and a video of his fridge here.

John's fridge is a truly magnificent piece of engineering. I decided that it would be a pretty awesome project to see if I could improve upon it. Hence, this project was born.

My goals for this project are as follows:

Modify a refrigerating unit to launch beer/soda cans
The direction and range of this launch must be definable by the user
The launcher must not be excessively dangerous
Ideally, the user would be able to simply press a button on a remote control and the can would launch to their position automatically.
The beer/soda must be cold.

The project will undergo several phases, including design, proof-of-concept, construction, and testing phases. The project may also spawn several smaller projects (such as portable can launching coolers). The project will be completed when all endeavors have been produced and meet their specifications.