Introduction
The Potato Launcher project was conducted to further the experience
gained from the UAH Rover I project
with pneumatic power and a custom remote control system.
From November 2005 through April 2006, we worked to create a
pneumatic, semi-automatic, remote
Adam Collins
Steve Conover
Chris Wolfe
controlled potato launcher using the UAH Rover I project as a base. As in the Rover I project, we
used a
Sharepoint website to collaborate and store discussions, files,
useful links, and our project calendar.

Figure 1: The final goal
Ultimately, the system would be operated remotely by a laptop. All
pressure, video, positioning, and firing would be done using a custom
GUI and a joystick. A video camera on the nose of the gun would be
our eyes.
Launcher Evolution
Such an ambitious system is not built all at once. Since we knew nothing
about potato guns when we started, we first built a prototype cannon,
followed by a mobile, more practical launcher. Ultimately, a modified
version of the mobile "bazooka" launcher will be build and mounted on
the final platform.

Figure 2: Launcher Evolution
Each new launcher served a purpose. The first prototype a merely an
introduction. It featured a ball valve that was difficult to turn, and
it was hard to transport. Nevertheless, its huge air tanks and long
barrel provided a valuable size comparison and consistently fired
projectiles further than any other launcher. The second launcher
featured a smaller air tank, short barrel, and a new butterfly valve fir
firing. The launcher was light, easy to transport, and was considered
the optimal size for our final system.
The next phase would be to add automated firing mechanism to the valve
so that a human does not have to turn the valve by hand. Work has
already been done in this area through the investigation of a pneumatic
firing piston using a secondary air tank.
Projectile Evolution
Initially we used red potatoes as projectiles for our launcher. As we
progress, however, we became aware of the limitations of using potatoes
for ammunition: sub-optimal shape, non-uniformity, and messy. Our
resulting measurements had massive deviation and our accuracy was low.
Thus, we began looking into creating a shaped projectile that would
serve us better.

Figure 3: Projectile Evolution
At first we desired to find a biodegradable solution because we did want
to recover all the shots. As a result we began
experimenting with Pykrete Rounds. Test launch
III was conducted to test the new rounds. The results are
documented here. One of the major failures
of the Pykrete round is their inability to stabilize. After much
discussion, we decided to move away from the biodegradable rounds and
move into an ambition "Smart Mortar" sub-project. The Smart
Mortar, or Smort, was to record accelerometer and pressure readings from
a flight as well as transmit video from the nose to a receiver on the
ground. Smort would have a stabilizing tail section and a parachute. The
first prototype was an empty shell and performed well. The second
prototype, contained the video transmitter
and power system, but was destroyed on launch.
Conclusion
As my April 2006 move approached, I concluded my role in this project.
Adam and Chris plan to continue work, however, so we may yet see things
come to completion.
Project Pages
- Working with Pykrete to create a better
projectile.
- On January 28, 2006 we completed our third
system test!
- All our project pictures on
flickr!
- Test Page for the wireless video
system.
- March 18, 2006 we failed Test Launch 5
(Yellowjacket w/ camera system)
Links
The following pages have been useful for us:
- Wikipedia: Spud
gun
-
Google Video: How to Build a Potato Gun
- Spudtech: Advanced Spud Gun
Supplies
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