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CpTn_lAw's combustion

Posted: Tue Aug 12, 2008 5:15 pm
by CpTn_lAw
Hello everybody!!
It's been a while since i posted a cannon ! i wanted to build a nice combustion cannon, without any other features. So here it is, a simple combustion cannon, nothing fancy...

Specs:
chamber : 4" x 2'
barrel : 2" x 3'
Ignition : standard piezo-electric BBQ lighter

A couple of friends and me shot it this evening on a lake, i must admit i wasn't expecting that much noise; the thing was extremely loud, i'd say as much as a 12 gauge. It's the first spudgun of this size that i make, the recoil is impressive too: the cannon managed to slip 20cm through my hands. We managed to shoot a golf ball out of sight, all across the lake that is about 150 meters long. The potato chunk went straight over it too.
I am the happy owner of a casio exilim EX-F1 that is well known now for it's slow-motion capabilities. Be sure that i will upload dozens of carnage videos ranging from 300 fps recording to 1200 fps. That will give me a pretty accurate estimation of the muzzle velocity of the projectiles I shoot.
We did find that nivea deodorant works great, better than axe; half a second of spray is enough to make a good deflagration. When burnt clean(dry fire for example) it makes a clear blue flame, when fired with a projectile, the flame is more "conical" and yellow-red.


The only thing i would have to say is a negative point on my cannon, is that there is no serviceable cap...

here are the pics, videos to come.

Image

Image

Posted: Tue Aug 12, 2008 5:20 pm
by SpudFarm
go change your signature, and good to have you back here :D

i thought you said you have lost almost all interest..

Posted: Tue Aug 12, 2008 5:26 pm
by Floyd
Looks good. The thing I am looking forward to is the carnage videos! Please Please hurry. Not many people have a camera that can record at 1200 fps.

Posted: Tue Aug 12, 2008 5:44 pm
by CpTn_lAw
Well, i had lost almost all interest...but you know...spudgunning is like sex, once you've tasted, you can't wait til next time.
I'll change the sig tomorrow, getting late here and 8hours of driving yesterday kinda killed me. Videos will be tomorrow, hosted on youtube. I'm planning on shooting an egg into a tree, golf balls into wet mudd, and potatos at all kind of things...we'll see!

I did not post the cannon so that i could have feedback like "woaw best cannon ever" , just to say that i'm still in the game, and that i wanna share it with ya spuders from all over the world ;) well, until tomorow, have some nice time ;)

Posted: Tue Aug 12, 2008 5:58 pm
by SpudFarm
can you please shoot a little pill bottle filled with red paint at something hard?

at 1200fps (A)

Posted: Tue Aug 12, 2008 6:12 pm
by starman
There's some of that Euro-PVC again. Just looks strange since there's nothing like it on this side of the pond.

My only real suggestion is to build yourself some kind of a handle and mount and neaten your ignitor.

How are you airing out the chamber?

Posted: Tue Aug 12, 2008 7:03 pm
by spuzi14
That's pretty cool. Can't go wrong with something simple right?

I am also curious about how you are airing out the chamber. I never have had to air them out when using Right Guard (although my stockpile is about to run out). However I also have never had a chamber that long.

Posted: Tue Aug 12, 2008 8:27 pm
by TwitchTheAussie
Gotta love the basics aye mate? Cant wait for the damage pics. And also:
spudgunning is like sex, once you've tasted, you can't wait til next time.
Thats true and going in my sig. :lol:

Posted: Wed Aug 13, 2008 2:29 am
by CpTn_lAw
Hehehe Twitch! yeah, to be honest, i was tired of pumping (no relation with sexual content :D ) my pneumatic (again...). tired of making burst discs for the hybrid, i just wanted something big and simple.
To answer some questions, I air the chamber by removiong the 2" cap and the barrel, and making big mouvements with the chamber (kinda looks like a rave-party dancer having some mushrooms...). You will have the videos today if the weather permits it!! I need to shoot it in the forest because the neighbors won't allow it in my garden XD really to much noise.

Posted: Wed Aug 13, 2008 4:30 am
by rna_duelers
Please I can't wait for the video!1200fps would be awesome,could you go a little more into detail on the camera you are using?Give it a little review if you will,because 1200fps without spending a fortune sounds good to me :P

I am actually working on a project much like yours at the moment,sick n tired of pump/airing my guns so I'm swapping over to the dark side :twisted: of combustion.There won't be any chamber fan,propane injection NOTHING just the essentials.

Ohh and by the way look out for those end caps,I had one of them blow out on me in Holland in the potato farming field we were shooting in.Got me right in the hand and it didn't tickle one bit.Good luck with your shooting and I hope to see a video very soon :)

Posted: Wed Aug 13, 2008 5:31 am
by CpTn_lAw
Okay, so here is a little off-topic review of the camera i'll be using with the videos and photos.:
Casio Exilim pro EX-F1

6 mega pixels bridge camera, 671grams. Has the capability of shooting 60 stills in one second at full res; HD (780p 30fps) and full hd (1080i 60fps) movies (H.264 native) at 18mbps, standard vga video (640x480 30fps) and high speed : 30-300 fps mode , 300fps, 600fps and 1200 fps.(336x96....)

Two stabilisers (hardware and lens), auto focus, stereo recording...and so many others....The camera costs 1000$ but the price really depends on where you buy it, i got mine for 800 euros with two 4GB SDHC cards.


As for the cap, it is not a "quarter turn" it is a fully screweable cap, and it did handle a full pressure shot, with a well enforced golf ball...

Posted: Wed Aug 13, 2008 5:35 am
by rna_duelers
Thanks for the camera info.But keep in mind about the cap,ours was shot about 30 times before it blew off.

Posted: Wed Aug 13, 2008 5:36 am
by CpTn_lAw
I will keep that in mind! ;) what do you suggest as a replacement?

Posted: Wed Aug 13, 2008 7:33 am
by psycix
Nice cannon, and even more nice is that camera. You can make really awesome vids using a high-speed camera and a spudgun. :D

Hey do you mind if I use this in my sig? :D
spudgunning is like sex, once you've tasted, you can't wait til next time.

Posted: Wed Aug 13, 2008 9:17 am
by SpudFarm
wait for it!


:twisted: