BanjoCannon




After about a billion delays, I FINALLY got this cannon finished. Special thanks to Aturner, too!
Although only the 1.5" rifled barrel is on the chamber, I'm going to have a golfball, tennisball, and 3"barrel for it at some point. The 3"� cam lever couplings make upgrading with no flow restrictions easy.

I call it the BanjoCannon because:
1. I'm from Nashville
2. I play the Banjo
3. large diameter Banjo coupling system
Logical, no?

Specs:
1. Chamber: 1' of clear 4"
2. Barrel: 4' of clear rifled 1.5"
3. Fuel: Aturner-style onboard/offboard meter
4. Ignition: BBQ ignitor in custom modifed Aturner-style grip
5. fan: blue/green LED chamber fan with no-wires-showing electronics box
6. loading: Breech loading by 3" Banjo Cam-Lever coupling system

Power:
-Chronied in the 300fps range. The best shot was 330fps, although since testing was very short I didn't get a great sample of readings. Further tests will clock the mean speed with greater precision.

Chamber, side-view
Chamber as seen from the rear
side view of the front of the chamber
Side view of the banjo coupling system
the breech cut on the barrel just below the banjo coupling
a nice shot of the rifled barrel
a view down the chamber
a view of the chamber down the breech
The end of the handle with the slick-lookin cut
Sparkstrip Closeup

The cannon was designed to be as aesthetically pleasing as possible while still being functional, economical, and powerful. I eliminated all exposed wires by making best use of the existing features of the cannon. For example, the chamber fan's battery box is secured to the chamber using two small machine bolts, which also function as the electronic connections. The BBQ's wires were hidden by running them through the 3/4" pipe and connecting them to the 1/4" bolts that hold the pipe in place.

The handle, while it may look odd, serves two purposes by having the 2- 45 degree bends. It not only brings up the handle from the Banjo coupling so one can grasp it easily but also changes the center of gravity of the launcher to be the most comfortable as possible. With the barrel attached, the cannon comfortably rests at a 30-45 degree angle when held with one hand. The original grip from which mine  is derived
(Spudtech forum's Aturner) does not need the bends when used with a standard 1.5" barrel and 4" chamber (there is sufficient room between the handle and the barrel that one's fingers are not uncomfortably positioned).

The fuel meter is also based off one I saw on a previous Aturner cannon. It is an onboard/offboard model, in that it is locked on the launcher but must be disconnected from the launcher for each charging. The charging apparatus is a propane source, regulator, ball valve, and female quick disconnect. I chose to not use an onboard meter for cost and simplicity. I chose not to use an offboard meter because I want to be able to have individual meters for all my cannons so I don't have to adjust the regulator ever. More importantly, though, with the onboard/offboard I can use a bulk propane tank, not a throwaway cylinder.

NIGHT SHOT PHOTOS!
I met with Aturner recently and got some great stills of the cannon shooting in complete darkness!
Frame1
Frame2
Frame3 Just the chamber fan
Frame4
Frame5
Frame6

If you look closely at the barrel, you can see the rifling lands!

Sample video, 1 of 3 taken



all images, text, and other content copyright 2006 John Shell, John@NeoSpud.com