A few notes before we start: There are MANY potato cannon recipes out there. I did not invent the mini potato cannon. I merely made my own out of inspiration. Second, this is more of a documentary than an instructable, as I made this before my instructables account. It gives you step by step instructions for what I did and pictures of the finished product but no pictures of the actual process. But you can still make your own very easily, and I will tell you what I did to make one.
**Disclaimer: This potato cannon shoots virtually anything small enough to fit in the barrel at a high velocity. This potato cannon also uses hairspray, which is extremely flammable. It is recommended that you wear safety goggle and keep flammable objects out of reach (yourself included). I am not responsible for any damage you cause to ANYTHING**
Step 1: Get the Materials
You will need:
1. Tylenol container (or any non-perscription medicine bottle)
2. Pentube (or any sturdy, hollow cylinder)
3. Piezoelectric sparker (anything with a high enough voltage will work, but the PE sparker is the smallest and the cheapest)
The piezoelectric sparker is probably the hardest to find. I got mine from an old barbecue lighter.
Tools you will need:
1. Hot glue gun
2. Soldering Iron (optional)
3. Sharp tool or rotary cutter
Step 2: Put It All Together
1. Poke a hole in the BOTTOM of the container.
2. Insert the pentube and apply hot glue liberally
3. Insert the electrode your choice in the top (tacks, nails, bolts, the sparker wires themselves)
4. Glue or bolt the handle of your choice. I used cardboard glued together then glued to the gun.
5. Connect the PE sparker to the electrodes. (picture)
Step 3: FIRE IN THE HOLE!
2. Get some hairspray or any flammable vaporous product
3. Puch your projectile half way into down the barrel
4. Take the spray and open the barrel. Two sprays should be enough. Like, Kgghg Khghg.
5. For the first test, put your thumb securely on the back of the barrel. On my first test, the barrel cap flew off because it wasn't a very high quality seal (the Tylenol containers fault) you can see why the seal is bad in the picture.
6. Aim away from yourself and other people and press the sparker.
7. You should hear a hissing sound and steam and smoke will come out the barrel. Since the projectiles are so small, they are almost impossible to find. Have fun!
Step 4: Troubleshooting
1. Common problem for my gun: The cap flies off if you don't hold it down.
2. Common problem again: Since the sparker wires aren't glued down, they tend to move. Just push them back into place.
3. Sometimes the gun won't fire, this is probably because of the above problem or it is because the barrel is to wet, either from constant repeated firings, or to much hairspray. If this happens just open the cap and let the hairspray drip out slowly.
I hope you people enjoyed my documentary.
If you have any questions you can PM me or post it in the comments.
P.S I hope to make a more sturdy one later. I'll post the link to the update in the intro.