My First cannon

[teh_luke]

Hi, just registered on this forum and thought I should share my first cannon.

I am 14 year's old and it took me roughly 45 minutes to an hour to complete this. It was fun and I plan on making another.

The barrel is roughly 7mm in diameter and I would like to know what ammo and accelerant is good. At the moment I am using this.


Thanks for looking.

~Luke~

[teh_luke]

Oh by the way the ammo above is a toothpick stabbed into an ear-bud/Q-tip.

[Carlman]

not bad, but really belongs on the mini cannon showcase rather than the combustion one.

i like the pistol design on it, although that short barrel is hindering performance.

[bigbob12345]

It is a nice mini especially for a first cannon and a longer barrel would give you a huge up in performance.

[Novacastrian]

As said by carlmen and bigbob a longer barrel (like about 5x the current length) will improve the velocity of any ammo you plan to put through your "pistol". What you need to invest in is a syringe without the needle and a can of butane. After figuring out the capacity of your chamber (fill with water and then pour the water into a measuring cup, or weigh it) you can work out how much fuel you need for a shot. Say your chamber is 100cc, then you would need 3.2cc of butane (3.2%).
As for ammo if the id of your barrel is 7mm you could possibly use frozen peas or 6mm bb's with some wadding to stop the bb rolling out of the barrel.
If i were you i would just make a crapload of the ammo you are using now.
Not a bad looking first attempt either.

Good luck with it all and welcome to Spudfiles.

Edit: Notice that you can edit your original posts too Luke, top right you will see an edit button, use that to avoid double posts

[BigJon]

Cool mini it kind of reminds me of one of those tiny revolvers.

[jimmy101]

Like others have posted, for that chamber size the barrel should be a lot bigger.

OR

You can increase the velocity if you cut the chamber size down and keep the barrel the same. A grossly oversized chamber significantly lowers the performance of a combustion gun. Wild-ass-guess, looking at the picture, your chamber volume is 10x the barrel volume. Cut the chamber size down to about the same volume as the barrel, you'll probably boost the muzzle velocity by at least a factor of two or three.

[teh_luke]

Thanks for the tip's guy's and Nova thanks for being so descriptive I'm going to do that today.

Also what would I use for the new 5x barrel?

[Novacastrian]

Well at a guess i would say to use PVC as your next barrel, from the look of your chamber (have you figured out the capacity yet?) the barrel i would suggest using would be around .50 cal. If you tell us the capacity we can most definantly tell you what size barrel to use. The choice of barrel comes down to whats handy for you.
With that sized chamber and the proper ammo there is no reason why it could not punch holes through stuff. That said if you put tight fitting ammo in it chances are that it will fail somewhere, what exactly is the chamber made from? It looks like glass, not a good choice for a chamber!

Edit: Well after thinking logically i figured it can't be glass if you have a hole in the base of it.

[teh_luke]

Awesome, I haven't figured out the capacity yet. I will soon but I'm just testing something. When I find out I'll post. Also the chamber is plastic. It is the smallest plastic peanut butter jar you can get. I Didn't think that if i made it out of glass I'd be able to get the pin's through to create the spark? Anyway it's a thin plastic about as thin as on a Water bottle or Coca-cola bottle.

[Novacastrian]

Here is one i prepared earlier, just for a visual reference to proper <a href="http://i182.photobucket.com/albums/x281 ... nis003.jpg"> C:B ratios</a>

[teh_luke]

Awesome What is it all made out of?

Oh and also, what is the barrel?

[Novacastrian]

Here is the link to the particular cannons home <a href="http://www.spudfiles.com/forums/12-7mm- ... tml">Click Here</a>

[teh_luke]

Oh thanks