Build Your Own Marshmallow Cannon
By Joe HudyAssembly Time: 5-8 Hours
Skill Level: Intermediate

Completed Cannon

Don't forget the marshmallows!
Step 1: Prepping the Parts for Your Cannon

Before you get started, make sure you have all the parts you need. Cut pieces are not pictured. You will need to cut them yourself. PVC glue needs to be twisted while fitting together. It makes a better seal. However, there are a few spots where twisting can't be done.
Click here for the complete parts list featured on Make Projects.
Step 2: Cutting the PVC

Cut all the pieces of pipe to the dimensions below:
4 - 1 1/2" x 2 1/4"
1 - 1 1/2" x 6 1/2"
1 - 1 1/2" x 10"
1 - 1 1/2" x 3 7/8"
1 - 1" x 2 1/2"
1 - 1" x 2"
3 - 3/4" x 1 1/2"
Make sure you have everything you need and be very careful not to cut yourself when cutting.
Make sure you have everything you need and be very careful not to cut yourself when cutting.
Step 3: Lay Out All of Your Pieces


Dry fitting the entire electronics project beforehand is a great idea. You'll notice that some of the pieces may need to be sawed down to fit correctly. Take your time when lining up the handle; it can be a little tricky. Also make sure you keep everything level.
Note: Draw out guide marks to help you know when you've pushed the pipe in far enough.
Step 4: Assembly of the Base


Start from the bottom and work upwards. You must work quickly – the PVC glue dries very fast. Spread the glue around the short pieces and inside the shaped pieces. Making sure everything is level, then push and twist together. If everything is not level, the later pieces you assemble will not fit.
Tip: After inserting all the pieces, lay them flat on a table and push to make sure the whole base is level.
Note: For a better seal where applicable, twist the PVC pipe while fitting together.
Step 5: Assembly of the Other Pipe Pieces


Using the same method as above, piece together the next set of parts:
1 1/2" x 12" one on each side
1 1/2" x 6 1/2" in the center
Step 6: Glue the Pieces Shown




Step 7: Setting the Handle
Glue a piece 1 1/2" x 10" into the two T pieces. Set aside.
Glue together part of the handle.
Glue the two together.
Step 8: Glue the Handle Piece into the Center Piece

Step 9: Gluing the Cannon Ends



Step 10: Glue Cannon Barrel


Step 11: Glue the Handle to Cannon





Step 12: Attaching the Sprinkler Valve

and use PVC tape for all screw fittings.

and insert other adapter.
Step 13: Assemble Pressurizing End of Cannon

piece into PVC.


Step 14: Continue with Pressurizing End Assembly


Step 15: Final Touches and Test Launch

Paint your launcher and let it dry. Put a PVC 12" into the top where the marshmallow will be loaded and fired. Solder the wires from the sprinkler valve, switches and extra wire to battery pack and hide the battery in Altoids tin.
One switch will be your safety, the other the fire. Load the marshmallows. Pump with bike pump to 30 psi. Flip your safety off and fire.
Note: Take note that the marshmallow will go far, so make sure you have a safe area to launch them.
Warning: Only pump the air cannon to 30 psi. Any more could result in damage to cannon or yourself.
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