My first "Advanced Combustion"

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
sgehring
Private 4
Private 4
Posts: 71
Joined: Tue Nov 21, 2006 11:36 pm
Location: Idaho

Tue Jan 09, 2007 10:08 pm

I have built a couple of big air powered guns/cannons and wanted to try Combustion's and to make something a little more "advanced" than the basic hairspray combustion and here it is.
I am going to call it he "Black Mamba", don't know why but it got a good sound to it. Here are the specs. The chamber is 4" sch 40 PVC well casing. The chamber is just a little shy of 400 cui when you add in the 2" elbows for the over/under configuration. I have three barrels for it. The one attached in the pictures is a 4 foot golf ball barrel made from two pieces of sch 40 sleeved together. It is a breechloader. The tee with extention rotates to the right like a bolt action rifle. The second barrel is a six foot long 2" "tater" barrel. The third barrel is a 10 foot golf ball barrel made from sdr 21 sleeved in 2" PVC sch 80 electrical conduit. All barrels have camlocks and are interchangable with all of my other guns. The gun uses metered propane at 45psi and metered mapp gas at 48psi to get the correct mixture. The chamber has a 80mm computer fan. It is controlled from the firing handle by a toggle for the fan and a push button for the stun gun spark. The handle was purchased form the infamous Gort-ster. Tremendous quality and quite frankly I do not think I could of made it for what I paid for it, and had the quality and reliability. When you include in the 4" PVC saddle to mount it all up,the hose clamps and even the 8 AAA batteries! I chose not to use the hose clamps at this time. I cut spacers/wedges from a piece of the 4" PVC. They are about an inch wide of various lengths and then epoxied them to the outside of the chamber and then the gas cylinder holder to them. This gave three long beads of Loctite epoxy that is rated for PVC. One on either side of the holder and one down the center for three places of support. I dropped the chamber with the cylinder and metering pipe on the concrete twice to see how it held up and it didn't break. The barrel support is also epoxied. If it becomes a problem later on I will use the hose clamps. Not pictured is a "tactical" sling I made for supporting the gun while firing. It makes it a lot easier to balance. Thanks Gort for your help. Let me know what you think guys your opinions matter to me.
http://img226.imageshack.us/img226/6295/1000585kz6.jpg
http://img444.imageshack.us/img444/5549/1000586ef6.jpg
http://img70.imageshack.us/img70/4127/1000587sk0.jpg
http://img444.imageshack.us/img444/7223/1000588ir8.jpg

I am going to try to add a few more pictures;
http://img483.imageshack.us/img483/8514/1000590qw4.jpg
http://img207.imageshack.us/img207/5240/1000591zw8.jpg
http://img224.imageshack.us/img224/636/1000595ey9.jpg
http://img483.imageshack.us/img483/8451/1000596ok5.jpg
Last edited by sgehring on Wed Jan 10, 2007 11:40 pm, edited 1 time in total.
User avatar
singularity
Corporal 5
Corporal 5
Posts: 982
Joined: Mon Jun 26, 2006 10:53 pm
Location: someplace
Contact:

Tue Jan 09, 2007 10:45 pm

looks nice, everything is very clean but why don't you just put the pictures in your post instead of links, you can use the img button in the post window. remember to press the button once before and once after the url of the image.
be sure to check out my <a href="http://www.spudfiles.com/forums/ak-styl ... 9.html">AK Styled Vortex Gun</a> and my <a href="http://www.spudfiles.com/forums/at-4-t9627.html">AT-4 Rocket</a>

upcoming projects... finalized clip fed BBMG and ball point pen sniper
sgehring
Private 4
Private 4
Posts: 71
Joined: Tue Nov 21, 2006 11:36 pm
Location: Idaho

Tue Jan 09, 2007 10:47 pm

I've tried before with no sucess to post the pictures that way but with no luck..I think I am going to try a different 'host" for the pictures other than imageshack. Thanks
User avatar
Pyro Ninja
Specialist 3
Specialist 3
Posts: 351
Joined: Mon Oct 09, 2006 7:11 am
Location: Australia

Tue Jan 09, 2007 11:00 pm

Very good looking cannon
clean, well constructed
great job
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Wed Jan 10, 2007 12:21 am

sgehring wrote:I've tried before with no sucess to post the pictures that way but with no luck..I think I am going to try a different 'host" for the pictures other than imageshack. Thanks
Nice gun!

And for the image hosting use photobucket it already gives you the [img] links and even hyperlinking links e.g <A HREF="URL HERE">Link Here</a>
User avatar
CS
Moderator
Moderator
Posts: 1837
Joined: Fri Feb 18, 2005 5:32 pm
Location: Southern Utah

Donating Members

Wed Jan 10, 2007 12:59 am

Noice gun!

Pictures are a little small, but from what I can tell its a sweet cannon! I've considered the construction of my own over/ under configuration cannon. I'm undecided as how to mount the handles on the gun itself. All the configurations of handles I've seen on O/U's seem rather uncomfortable. So I ask, how does that handle set-up work for you? I assume your left-handed?

Nice paint! Looks like you got gloss on the barrels, and stuff. Then semi-gloss on the chamber, and cylinder holder. On the subject of the propane cylinder, why did you mount it with the cylinder valve pointing forward, while hook up is at the rear of the cannon? It seems as if you mounted the cylinder in the other direction, that the hose length would be reduced, and a less problem with 'snagging'.

One more question if I may. How is that small diameter ball valve for venting working? Most venting ball valves Ive seen are fairly large. Although I imagine a small diameter valve would be nicer for the fact of shear size, and that they require less force to open.

Again nice cannon, looks like lots-o fun!
User avatar
experament-u2
Specialist 4
Specialist 4
Posts: 469
Joined: Tue Dec 26, 2006 11:18 pm

Wed Jan 10, 2007 1:53 am

that is a nice gun from wat i can see but bigger pics would be beter i cant see it very well :(
User avatar
Tyro
Specialist
Specialist
Posts: 154
Joined: Sat Oct 07, 2006 1:03 am
Location: The Land of Plenty! (Aus)

Wed Jan 10, 2007 2:31 am

Your first "Advanced Combustion"....
Eh. I can't see what's what, advanced is an understatement.
na just kidding. Nice gun. Does look pretty high tech!
sgehring
Private 4
Private 4
Posts: 71
Joined: Tue Nov 21, 2006 11:36 pm
Location: Idaho

Wed Jan 10, 2007 9:42 am

Pimm I appreciate your comments. I will try to get some better pictures up. I am right handed. The reason the handle was postioned the way it was is that when it is slinged over the shoulder you would have to reach over the barrrel to reach the handle on the other side. This makes it balance real well doing it this way. Balance was the reason I put the cylinder on the bottom also. I put the cylinder out the front to match up to the hose I had. It is a 2 1/2" foot ,300psi air hose with the swivels on the end and I did not want to cut it up. The smalll loops of pipe at the back of the cylinder holder are 1 1/4" pvc that the hose is routed through to keep the hose out of the way. This keeps it close to the side of the gun. It does not snag. They also work for mounts for a collapsible stock made of 1"pipe that slides into the 1 1/4" pipe perfectly. The main paint is satin black however the barrel is gloss. It is the barrell on my "maulernator" and is used on all my guns. The size of the valve makes it lighter on the end. You just leave the fan on a few seconds longer to vent.

I have added some closer up pictures I hope this helps.
Last edited by sgehring on Wed Jan 10, 2007 11:54 pm, edited 1 time in total.
User avatar
sgort87
Corporal 5
Corporal 5
Posts: 994
Joined: Sun Sep 18, 2005 10:32 am
Location: Lockport, Illinois

Donating Members

Wed Jan 10, 2007 11:43 pm

VERY nice Shane! I love it. I also think the pictures don't do the launcher justice. I need some close-ups or that fine work of art you got.

Tony, to see how to hold such a gun, click on my new avatar.
Scotty
Specialist
Specialist
Posts: 114
Joined: Tue Jan 09, 2007 3:00 am

Thu Jan 11, 2007 7:55 am

Nice One I want plans!
Sweet job bro. :D
spudfellow
Private
Private
Posts: 4
Joined: Wed Jan 03, 2007 9:18 pm

Thu Jan 11, 2007 11:18 am

sweet cannon man..i really like it. nice job!
Post Reply