Build Your Own Marshmallow CannonBy Joey HudyTime required: 5-8 Hours Difficulty: Moderate |
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Don't forget the marshmallows |
Step 1 – Prepping the Parts for Your Cannon
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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
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Cutting the PVC Pipe
Cut all the pieces of pipe to the dimensions below. 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
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Dry fitting the entire 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
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Start from the bottom and work upwards. You must work quickly, for 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.
After inserting all the pieces, we laid it flat on a table and pushed to make sure the whole base was level.
Note: For a better seal where applicable, twist the PVC pipe while fitting together.
Step 5 – Assembly of the other pieces of pipe
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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
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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
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Glue them together |
Step 10 – Glue cannon barrel
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Glue bushing & small piece into top of X piece |
Step 11 – Glue the handle to cannon
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Glue small piece into small elbow |
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Glue T piece into both small pieces |
Glue small piece into end of T |
Step 12 – Attaching the sprinkler valve
![]() Use PVC tape for all screw fittings |
Attach electronic sprinkler valve and insert other adapter |
Step 13 – Assemble pressurizing end of cannon
On the opposite end, glue brass piece into PVC
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Screw pieces in as shown |
Brass pipe T Remember to use PVC tape
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Step 14 – Continue with pressurizing end assembly
Attach bike tire valve |
Attach Pressure Gauge |
Step 15 – Final touches and test launch
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Paint your launcher and let 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.
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 30PSI. Any more could result in damage to cannon or yourself.


Don't forget the 











Glue them together
Glue bushing & small piece into top of X piece
Glue small piece into small elbow
Glue T piece into both small pieces
Glue small piece into end of T
Attach electronic
On the opposite end, glue brass piece into PVC
Screw pieces in as shown
Brass pipe T Remember to use PVC tape
Attach 
