SpudFiles

Not done yet, still waiting on my golfball barrel from BCARMS, but i couldnt resist trying it out.

This is my second gun, basically a redesign/scale up of the first one. salvaged a few components from the old one for this one as well.

4" chamber, measured out to 3600cc
115ml meter pipe with fixed 20psi regulator
80mm Vantec Tornado 83 CFM chamber fan running at 18v on 2 9v bats
2 gap bbq igniter ignition
threaded interchangeable barrel


the gun is WAY loud, about 10g shot gun loud. Most of that im hoping is due to the temp barrel im using which is only 2ft long. Also getting about a 10" long flame shooting out of the barrel....

I have no idea what the range is. My best shots on the old gun would push 225 yards. This one shoots past that point and is still going strong way past where i can see it. Hopefully my golfball barrel comes in this week for some real shots next weekend. Its unreal how fast the golfballs move.

The chamber fan is overkill, but it sure gets the job done. Vents the chamber in about 10seconds.

pics are cruddy, but what can ya do.

Those bell reducers sure do look weird. Haven't seen any with that shallow of an angle. Are they nsf-pw, by any chance?

im sure they're DWV.

they're 4" to 2" reducers.

My guess would be that they are DWV as well. I have some PW 2"x1.5" bell reducers and they are made with smooth curves instead of sharp angles.

I like the double length meter pipe. How do you make sure it's at the right pressure? That looks like a regulator connecting to the tank but I don't see any pressure gauge. Do you just guess/time it, or is it configured to fill at tank pressure?

Also, how long ago did you order from BCARMS? I placed an order for some golf ball pipe over two months ago and I'm still waiting for it, though I've pretty much given up on waiting and am now trying to acquire some through different methods.

Its a fixed 20psi regulator from a camping stove. Its so big because ive got so little PSI, but it was cheap, so im using it.

I spoke with BC a few days ago about the shipping delay, supposedly he had a mix up with his supplier and got behind on his orders because of it. Said its taken care of now and the barrels should be going out shortly, or at least i hope so.

Yep, your shots are loud because of your relatively short barrel. At least a couple more feet will make a big difference in loudness as well as increased projectile performance.

MortarArmy wrote: The chamber fan is overkill, but it sure gets the job done. Vents the chamber in about 10seconds.

Why do you say the chamber fan is overkill?... It's an integral part of an "advanced combustion".

MortarArmy wrote:pics are cruddy, but what can ya do.

Wellll...you could take some that aren't...and then you don't post the ones that are... Actually only the first one is a little blurry.

I like the U shaped meter...a little different flavor there. The hose connection to the chamber is a little worrisome. I would suggest a hard piped, much shorter elbow for that.

unfortunately, cell phone camera is all ive got at the moment. good camera took a trip to the electronics grave yard a while back.

Chamber fan is over kill because its an 83CFM fan, vs your typical 30cfm computer fan, this thing will literally remove chunks of flesh if you happen to touch a blade while its on....i know, ive done it more than once. its also super loud.

Whats wrong with my hose connection to the chamber? its threaded on one end, hose barb on the other. threaded end is tapped into 2 layers of PVC. I did it that way so i could be 100% sure that the fittings on the meter pipe were as tight as they could be. Also makes installation much easier.

That regulator gives out low pressure, i presume? thats a huge meter volume....

MortarArmy wrote:Chamber fan is over kill because its an 83CFM fan, vs your typical 30cfm computer fan, this thing will literally remove chunks of flesh if you happen to touch a blade while its on....i know, ive done it more than once. its also super loud.

Whats wrong with my hose connection to the chamber? its threaded on one end, hose barb on the other. threaded end is tapped into 2 layers of PVC. I did it that way so i could be 100% sure that the fittings on the meter pipe were as tight as they could be. Also makes installation much easier.

Because the hose becomes a part of the chamber and directly subject to the combustion forces...it's a weak point.

Re. the 83 CFM....nothing at all wrong with that. The loudness just makes for impressing the spectators....

Thats 1/4" reinforced nylon braided hose with a working PSI rating of about 300 PSI and a burst strength around 900 psi. I think im good!

Last gun used the same design, same hose, didnt have any problems.

This cannon looks pretty damned good, but I would suggest a different handle...

I like the way you've mounted the propane tank into a piece of 3" pipe, and not just slapped it on there, and I also like the project box. Good job!

i like my handle. lets me fire it like a shot gun. looks ghetto, but it works.

I know, I was just commenting that it looked a little small. If that tee is 2" (which is what it looks like), the bottom of my hand would be hanging off the end of it.

MortarArmy wrote:Thats 1/4" reinforced nylon braided hose with a working PSI rating of about 300 PSI and a burst strength around 900 psi. I think im good!

Last gun used the same design, same hose, didnt have any problems.

I'm familiar with the materials, it's not good practice.

You seem a little defensive regarding other's suggestions. There's no need to be. You've built a decent cannon here and posted it for opinion from other spud gunners. Maybe give em a little space...

starman, others have used hose for connecting a meter pipe to their cannon before. It doesn't do any harm.