Intro: Cheese Ball Machine Gun
This project was a fun one. I went through probably close to a thousand cheese balls before it was all said and done. Even so, the local wildlife had them cleaned up no more than a day later.
This is built around an electric leaf blower with a little PVC pipe for the barrel. The leaf blower acts as a high volume air supply that propels the cheese balls, and a little bit of manipulation of the air flow ensures that the cheese balls feed smoothly. I'll get into that part in later steps. The embedded video above demonstrates the full process to make this project and of course written instructions will follow.
- Lots of Cheese Balls
- Leaf Blower
- 1" PVC Pipe
- 1" PVC T Fittings (x2)
- 1" PVC Coupling
- 1" PVC End Plug
- Stiff Wire (Music Wire or Clothes Hanger Wire)
- 3/8" Nut, Bolt, & Washers
Step 1: Barrel Mount
The first step to this project is to figure out how to connect a 1" PVC barrel to the business end of whatever leaf blower you happen to be using. My blower conveniently came with a detachable piece to allow a leaf bagger to connect with the front end. This made it easy to secure a PVC fitting into the connector with epoxy which then snapped right on to the blower. I used a T fitting so that it would take up more space in the opening and less epoxy would be necessary to fill the gaps. The part of the T that is submerged in the epoxy has an end plug pressed into it to keep epoxy from leaking inside while it cured. I used duct tape to hold the PVC in place and seal off the openings while the Epoxy was poured.
Supposing your blower does not have this same sort of detachable bagger fitting you may have to devise an alternate method to seal a PVC fitting into the opening. Creating an attachment with fiberglass may be a good option, or you could simply tape the fitting into the blower for a temporary solution.
Step 2: Barrel & Hopper
The barrel of this cheese ball machine gun is made from 1" diameter PVC pipe with a T fitting toward the back end to attach the hopper. A small length of PVC pipe connects to the rear of the T fitting which will be what joins the assembly to the fitting epoxied into the leaf blower. This short piece of pipe will get some modification in the next step.
I'm using a piece of pipe about 2' in length for the main part of the barrel. The length is pretty arbitrary here, it may work better or worse at various lengths. I just thought 2' looked good.
The hopper is nothing more than an empty container that cheese balls are sold in. A hole is made in the side so a piece of pipe from the top of the T can pass through, and a piece of coupling is pressed on from the inside to lock the container in place. I also added a wood block to help support the hopper by resting it on the front of the barrel. Holes are drilled through the lid of the container as well to relieve any pressure that might backflow into it.
Step 3: Creating a Venturi to Feed Cheese Balls
If you simply put together this project as I've so far described but miss this next step you would find it doesn't work very well at all. Air would come from the leaf blower and feed right up into the hopper, strongly resisting any cheese balls from falling into the barrel and being shot out the front. We need the air flow to instead be sucking cheese balls into the barrel. We'll accomplish this by adding a venturi into the small piece of pipe that connects the barrel to the blower.
A small ramp is cut from a piece of scrap PVC and sanded down to fit inside the small section of pipe. This is glued in place with PVC cement and oriented to direct air flow away from the opening in the T fitting that faces the hopper. This will cause the high pressure air from the blower to pass by a layer of still air below the opening in the T fitting. As the high pressure air passes by friction will drag the still air along with it, creating a vacuum in the hopper that will suck cheese balls right into the barrel.
Step 4: Agitator
After the last step has been completed and the barrel joined to the blower the cheese ball gun is fully operational, but an optional step that can increase the feed of ammunition further is to add an agitator into the hopper. I drilled a hole through a short bolt which I then mounted in the back of the cheese ball container with washers and a nut. Passing through the hole in the bolt is a piece of high carbon music wire that is bent in such a way as to allow me to stir up the cheese balls while firing. This allows me to clear occasional jams and in general helps to keep it firing smoothly.
All that's left to do is fill up the hopper, turn on the leaf blower, and fire away!