SpudFiles

This is my first multi-barreled cannon and also my first propane setup. All ABS to PVC parts were glued with ABS to PVC transition cement and nuts and bolts reinforce all fittings that weld the two together.

Combustion chamber 12" x 4" (main chamber).

Breech = 2"

Softball barrel = 32" x 4"from base of ball to tip.
(A bolt sits 4" above the main tube of the barrel to seat the softball high)

Tennis ball barrel = 36" x 2.5" PVC (thats where it seats)

Potato barrel = 48" x 1.5" ABS (new length)

Golf ball barrel coming soon (I plan on 72" x 2")

Propane and meter system with valve from a propane torch and a blowgun for the other. This screws into a tire valve at the base of the combustion chamber. Hose is from a broken bike pump.

BBQ igniter glued into a hole. Nothing special. Very reliable so far.

Softball distance measured with a GPS = 885 ft. Who says short barrels can't shoot far? Haha

I MAY do a damage video for you destructive obsessive people. 3/4" plywood isn't cheap so I have to find something else. Plus it doesn't fit in my car.

Jeff

EDIT: Here's some damage video for you if you haven't seen it in the other thread.

[youtube][/youtube]

title is a little bit deceiving because I thought there was multiple barrels on the cannon. I didnt know it was multiple detachable barrels. Oh well not a big deal.


you could get a sheet of wafer board which is really cheap.

Very nice! I love big cannons

Davidvaini wrote:title is a little bit deceiving because I thought there was multiple barrels on the cannon. I didnt know it was multiple detachable barrels. Oh well not a big deal.

I see that. I changed the title to be more specific.

Jeff

get a vid up!
be sure to show all the barrels shooting.

nice propane meter and i have said mine about the cannon before

ahh Jeff i see u got that meter built, looks good. have u found a good pressure for it yet. also i shoot baseballs out of my howitzer but your gun has inspired me to add a softball barrel too. g/j.

Excellent work on the meter. I don't think I've seen anyone use a blowgun on one, usually just ball valves.

Good to see someone thinking outside the box

I find that 36psi gives me the furthest launches with the softball attachment.

Jeff

I love this gun...More people should be using 4" PVC/ABS. It rules.

n-strike wrote:I love this gun...More people should be using 4" PVC/ABS. It rules.

What? A good percentage of combustions use 4" pipe

Oh sorry, I meant for pneumatics...I know this is a stupid reasoning, but it's because for me, the bigger, the better. And yes I know that is not the case. I just go for size.

Very nice. The use of the blowgun for the meter is a great idea. Just wondering if you have any issues with your C:B on the softball barrel, It's a 1:3 from your given measurements, does it seem to kill performance... of course 300yds with a softball from a combustion isn't bad... nice work though, very clean.

daxspudder wrote:Very nice. The use of the blowgun for the meter is a great idea. Just wondering if you have any issues with your C:B on the softball barrel, It's a 1:3 from your given measurements, does it seem to kill performance... of course 300yds with a softball from a combustion isn't bad... nice work though, very clean.

The softball is held 4" above the bottom of the barrel with a bolt. Doing that with the softball barrel makes the combustion chamber even bigger than it normally is with the other barrels. C:B ratio is about .57/1 for that barrel. It packs a pretty good punch.

Jeff

=0 Wow, I don;t think I've ever seen a combustion with what looks like a barrel thats lots larger than the chamber before. I like all the bore size options. (hmmm.. gotta try to implement that in my next mini)
I like it =)

Well, I think you have your math wrong. I didnt think about the 4" gap as chamber, but your right, it's definitely part of the chamber, but with a 12" long chamber + the 4" gap, is only 16", and the remainder of the barrel is 32".... so you have a C:B of 16:32, or 1:2... which is pretty close to the "max power range" of between .5:1 and 1.5:1... which I guess answers my original question. Again I would like to say great job Jeff.