Small Potato Cannon

The small potato cannon is a smaller and much safer alternative to a regular potato cannon. It uses a lighter with piezo igniter to ignite rubbing alcohol in the combustion chamber and make an explosion and push the ammunition out the barrel at a very fast speed.

I decided to build this because I like to make guns and other things that shoot projectiles. I wanted to make something that had more kick to it than a gun that I made out of technic Lego pieces a year ago that shoots 1x3 technic rods with a working magazine too. I did some research and found out that potato cannons exist and that they shoot very far and fast, but I'm only 16 in 10th grade and would like to not have to pay property damage for breaking anything. So, I scaled the cannon down a little to still get the firepower I was looking for.

Side note:(I called a small potato cannon because the term mini didn't fit very well because it's larger than another one I made out of a small flashlight that fits the term better)

1. Lighter with a piezo igniter
2. Hot glue gun with sticks of glue (Plug the glue gun in and give it time to heat up before using it)
3. Rubbing alcohol (there should be a warning label on the bottle that says flammable)
4. 2 Empty sparkling ice bottle
5. Drill with 21/64 inch drill bit
6. Straight plastic drinking straw
7. Q-tips
8. X-acto knife
9. Dark colored marker
10. Clear packing tape
11. Safety glasses

Grab the two Bic pens and take the caps off along with the ink cartridge and the part that holds the ink cartridge. Then, grab the marker and x-acto knife and draw a line right before the end piece of the pen then, cut where you drew the line on the pen. Then, you can dispose of the ink cartridge, the piece that holds the ink cartridge, and the butt end of the pen that was just cut off. Then get about an inch of the clear packing tape and put longways on a flat surface. Then take the two pens and put the flat ends together and put it on the tape longways and roll the pens on the flat surface until the pens are taped together. Then, grab the straw and using the marker, draw a straight line longways down the straw and cut down that line using the x-acto knife. Then, grab the pens that are taped together and put them inside the now cut straw. Then, get a piece of tape the length of the straw and do the same process as when you taped the pens together.

Take the cap from one of the sparkling Ice bottles and get a drill with a 21/64 inch drill bit. Then, with the marker make a dot in the middle of the cap. Put on safety glasses then, drill a hole in the cap using the drill and insert the barrel in the hole in the cap about half an inch deep. Then, glue the barrel to the cap by gluing the inside and out of the cap of the cap to make an airtight seal. Don't get glue on the sides of the inside of the cap otherwise the cap won't go back on the bottle correctly.

Grab the both of the sparkling Ice bottle and at the bottom of the bottle draw an outline where the bumps at the bottom stop and the bottle becomes perfectly circular. With your X-acto knife cut out the outline you just made on the bottles. Once both of the bottoms of the bottles are cut off slide one of the other bottles over the other and glue them together. Then put the hot tip of the glue gun on the end of the bottle that is close to the barrel so that the plastic of the bottle shrinks around the other bottle.

Take the other cap from the other bottle and make a mark where the lighter is in the middle of the cap with a marker. Then use the drill with the 21/64 inch drill bit to drill the mark of where the lighter will go. Put the lighter in the hole in the cap and glue the lighter in the hole with the hot glue. Don't get glue on the sides of the inside of the cap otherwise the cap won't go back on the bottle correctly.

Now with all of the parts assembled the last thing to do is screw the barrel onto the bottle that is inside of the other one and the cap with the lighter on the other bottle. Now the small potato cannon is done.

Grab the rubbing alcohol and put a few drops in the bottle without the barrel on putting your palm on the part where the cap goes on and shake the bottle to mix the air and rubbing alcohol vapor. Then, put the ammunition in the barrel which can be whatever fits in the barrel and doesn't move, but if you want to shoot something that can slide around in the barrel and can fall into the bottle put something behind it to make a seal so the ammunition doesn't fall in the bottle. Then press the lighter igniter and watch the ammunition fly.

side note: (the video attached is in slo-mo)