How to Build a Water Bottle Cannon

by themathnight in Workshop > Woodworking

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How to Build a Water Bottle Cannon

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Hey my name is Gavin Rappleye and I love making things and this is a great way that you can reuse old parts from around the workshop to make a entertaining and exciting water bottle cannon. LET'S GET TO IT! NOTE: the measurements that i give are up to interpretation and if you have similar pieces let's use them to save the planet:}

Supplies

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1/2in 90 PVC fitting

1/2in 5.5in PVC

1/2in 21in PVC

3/4in thin wall PVC (9.5in)

3/4in pvc coupler

1 1/2" in wood screws (i did not use them but you should)

silicone

2 -liter bottle

#115 x3 O rings (7/8in ID, 1-1/16in OD)

wood:

3X 12in by 4in and 2X 4in by 4in

(3/4in thick)

air compressor attachments (will be different for you):

hose barb adapter

tubing,

brass pipe hex bushing

and some other me specific parts that will be different for you/

Assemble the PVC Stucture

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this project uses a PVC structure to provide airtightness to your system.

1). lay out your PVC pieces

2). attach the 21in 1/2in PVC to the 1/2in 90 degree joint and attach the other end of the joint to the other 1/2in pipe.

3). slide on the 3/4in thin wall PVC (9.5in) and slide on the 1/2in coupler

Making the System Airtight

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air is a very versatile resource that can go almost anywhere you will let it - so we don't let it. because we have 2 different PVC pipes, we will apply silicone to the seal to prevent air from leaking. we will also add O-rings (found at Home Depot) to make the seal where the water bottle will go as airtight as possible.

Adding Air Parts

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this part is a little confusing and iffy because it depends on the setup that you have or get. for example I had an adapter that connected through a series of adapters before getting to my air source. if you don't have anything you can drop by Home Depot, tell them what you have and they will more than likely help you out.

Building the Base

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with this you have 2 options, you can make the base out of wood, or you can 3D print it. either way they both turn out great but unless you have a 12 by 12 build plate you are going to have to chop up the file and if you want to go ahead but I personally think that the wood-way is easier and allows you to reuse the pieces of scrap wood that you have lying around. or you can choose to not mount it and keep it as a glorified hand cannon that you use to show your wrath to all who oppose you :)

The 3D Printer Way (the Nerd Path)

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the steps to 3D printing are different per the 3D printer you have so load up the filament and into the slicer in the way that your printer says it should be. but if this is the way you chose it should not be too big of a deal because we are problem solvers.

The Woodworking and Hands on Way (the Man's Way) PT1 (cutting)

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alright, to start you are going to need some wood and if you have some 4X? lying around we can put it to work.

to start, you are going to need to cut the following pieces out:

3X 12in by 4in and 2X 4in by 4in as follows:

note that we as humans are naturally terrible at being perfect so if you mess up that is OK.

now for the three 4in by 12in boards we will set aside for now but for the two 4 in by 4in boards we will need to drill holes so the PVC pipe can fit through.

for me, this was a 1 3/8 in hole on the top and a approximately 1in hole at the bottom with lines cut out of it (see pictures) for this i used a spade bit and a drill press for the holes and a band saw for the lines that meet up with the side of the wooden piece.

The Woodworking and Hands on Way (the Man's Way) PT2 (Assembly)

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during this assembly I used screws to secure the top piece to both 12 by 4 pieces and then an inch from the bottom putting the bottom piece on and attaching the base board with 3 in as stabilizers on both sides. I used 1 in wood screws to do this (they were countersunk pretty deep), but I would recommend 1(1/2) in wood screws but if you have another similar size screw that works.

after you finish screwing the boards together, take the completed PVC pipe and stuff it through the top hole and bring it down through the bottom hole/wedge depending on how you have it.

NOTE a pilot hole is good to make before you screw in the screws

Finish!

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that is it! you are done! pat yourself on the back for a job well done! if you would like to make this waterproof or at least water resistant, I would recommend a primer and paint job after a good sanding job but as is it should be good! you reused the old stuff in your garage and made something useful.

OPTIONAL

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okay, okay you have a sustainable water bottle rocket cannon that is powered by air pressure and is made by you but how can you reuse more than just the wood and PVC? well if you have some 2-liter bottles or heck, you could even use 16 oz water bottles you could turn them into some really cool projectiles... just saying