My first, simple yet effective, potato cannon.

[Scourch]

Hey everyone. First, I'd like to thank the kind folks who had answered some questions for me a little while back.

That being said, I have for you some pictures and a simple video of the new cannon.

So what we have here is a basic combustion cannon made from ABS piping.

Barrel: 3" ABS pipe at 4' long
Combustion Chamber: 4' ABS pipe at 2 1/2' long
Ignition system: BBQ grill igniter
Propellant: Rightguard deodorant spray.

Now I wanted a nice clean way of handling the gun, preferably with a trigger and a handle. Also, as less wire as possible. The shorter I can make the wire, the less current is lost. So basically I had bough some 16 gauge wire, (I think it was 16) and simply crimped it to the the adapters and fitted them to the igniter. Total length of wire it approximately 3 or 4 inches in length for both ground and hot. The other end are attached to washers around two screws. Once I tested out the electrical system and all was hunky dory, I took a small piece of ABS, cut the top half off, bored a hole in the handle to fit the igniter and just cemented all of it together.













As you can tell, there's stickers still on it and the ends of the metal rings haven't been taped down. I plan on painting it and cleaning it all up. But in it's raw unappealing form, lol, there it is.

[youtube][/youtube]

The camera lady is my friend Simone, who, doesn't like loud noises haha. Hence why she is so far away. After the shot I was rained upon with potatoes. It was wonderful haha.

[spudtyrrant]

very nice job glad to see someone is getting information and putting it to good use. also for a spray & pray(aerosol combustion) i have found that starting fluid works the best. i like spray &prays if i were you i would just keep it that ways even tho i already know people are going to be griping about adding a chamber fan and a metering system the most i would do is add a chamber fan starting fluid once you get it right only gets about 80fps less than propane i would also add some 3/8 inch rubber hose around your hose clamps for a nice clean look

[starman]

Reasonable effort for your first cannon.

Really only a quick comment regarding the 16 gauge wire you used. You aren't pushing any significant current at all through the spark circuit...lot 'o volts...almost no current. So in reality, you could use 24 gauge magnet wire and it would still be overkill for the application. Even then, you're only talking about a few inches of wire...current carrying isn't a problem, believe me.

You actually want to focus more on insulation of the wire instead of its gauge. You don't want any arcing at all...thin insulation can allow sparks to jump through to close-by returns or grounds.

[Scourch]

Ah I see, gotchya. Well to be honest all I did was find the wire that best fit the wire size that originally came with the igniter. But this one cannon was quite the process and learning experience. I plan on taking what I learned and building from there. Thing is, I am far from an engineer and know very limited stuff about circuitry and the mechanics of all that stuff involved.

For example, I have no idea how people put fans in their guns. I know the purpose of it, but I don't know how it fits into the cannon without it getting exposed to the combustion in the chamber.

But time will tell. it's a fun hobby.

Reasonable effort for your first cannon.

Really only a quick comment regarding the 16 gauge wire you used. You aren't pushing any significant current at all through the spark circuit...lot 'o volts...almost no current. So in reality, you could use 24 gauge magnet wire and it would still be overkill for the application. Even then, you're only talking about a few inches of wire...current carrying isn't a problem, believe me.

You actually want to focus more on insulation of the wire instead of its gauge. You don't want any arcing at all...thin insulation can allow sparks to jump through to close-by returns or grounds.

[Gaderelguitarist]

The fan put in the chamber IS exposed to the combustion. However the combustion is for such a short period of time that the fan is not damaged.

[Moonbogg]

Looks good. I think you may be able to modify your cannon to take metered propane and a fan...maybe even a spark strip. The power increase is significant. Once you learn how to build that, then the next logical step is the masterful hybrid of course