In this instructable I will be building a potato gun that is disguised as a minigun. You don't have to load it to use it as a prop but it makes for a good military or nemesis costume accessory.
Step 1: Materials
What you need:
2 10' piece of 1/2" pvc pipe
1 2' piece of 4" pvc pipe
1 5' piece of 2" pvc pipe
4" end cap
4" to 2" reducer
4 2" end caps
pvc glue and primer
paint of your choice
Step 2: Make the Combustion Chamber
Take the 4" pipe and cut it to 12" then put the reducer and end cap on.
Step 3: Attach the Barrel
Take the 2" pipe and cut a section 24" long and attach it to the cumbustion chamber.
Step 4: Make the Fake Barrels
Take the 1/2" pipe and cut it to 25" and cut one end at a 45 degree angle. do this 5 more times. Next you have to glue them onto the assembly and that is no easy task, I found it easier to use a hose clamp to hold the barrels in place while its glued.
Step 5: Make the Barrel Rings
Take the leftover 4" pipe and cut 2 thin rings and 1 wide ring and cut small notches where the barrels go with a dremel. Glue the rings on the barrel starting with the wide one first.
Step 6: The "motors"
Now its time to make what would be the electric motor that spins the barrel on the real model. Take some more 2" pipe and cut two of them to 10" and glue the end caps on. Drill to holes in each one and cut a 1/2" pipe to where about 11/2" sticks out. Put glue on the bottom of the 1/2" pipe and around the hole you drilled and put the pipe in the holes to make little dowl rods. Take some hot glue and go around the edges of the pipe and fill the inside of each pipe so it seals it. To check for leaks blow into one hole and listen for air leaks. These pipes MUST be completely air tight or the combustion chamber will leak.
Step 7: Attach Fake Motor Housing to Assembly
Now drill four holes in the combustion chamber, two on each side. Glue the fake motors onto the combustion chamber and seal each hole so its air tight. Drill a hole in the top of the combustion chamber so you can spray fuel in it.
Step 8: The Handles
Take a 1/2" 90 degree elbow and 8" of 1/2" pipe and aglue them to the rear og the combustion chamber by drilling a hole in the end cap. Glue the grill lighter to the top of this assembly. Make sure it sparks good before you seal it up. Next make a grab handle for the front. I made mine from a metal strap and wrapped it in electrical tape so it don't cut you.
Step 9: Painting
Once everything is set and ready to paint, take whatever color paint you want and start by putting light layers on the get heavier. using plastic paint from krylon works better. attach the grab handle when the paint dries.
Step 10: Finished
Once the paint is dry, stuff a folded paper towel down the barrel till it stops against the screw and spray some hairspray in the hole on top if the combustion chamber, wait a few seconds the push the button.