SpudFiles

This spring it came up in conversation with a new friend that I once upon a time was into building potato launchers. I dug my old 4"x2" coaxial out of the garage and we took it to his field and had a good time, and of course he wanted a bigger better launcher. Thus we constructed a 6"x3" (sch 80) coaxial piston launcher.

There are 2 Issues I need to sort out.

1. The launcher uses a 3/4" QEV to pilot the piston valve. To trigger the cannon we attached a male 1/4" quick disconnect to the fill side of the QEV then a regular air hose to a blow gun. (the thought being you could take the hose off for transit) Firing the cannon via that setup caused the qev to reseat, and thus reseat the piston valve. Separating the quick disconnect on the charged cannon, and kinking over the "trigger" hose both fired the cannon correctly. My assumption is there is too much restriction in the trigger line for correct operation. (I assume increasing flow in the trigger line will solve this issue)

2. My main issue, This cannon is big and heavy. The only tests I have done have been with the cannon strapped down to a big heavy router table. This makes the cannon not portable at all, and nearly impossible to aim. I was looking for ideas (pictures especially) of well built cannon stands. The stand will be a trailer to tow behind a 6x4 gator, incorporating elevation adjustments, and ideally windage adjustments. I would also like to include recoil suppression but that may not be necessary if the stand is rugged enough (but it would look cool).




So please share your thoughs!

Thanks

SplatteredStarch

EDIT: added promised pictures, someday ill get some better ones with less distracting stuff in the background.

this sounds impressive, get some pics when you can.

About the stand, I can't say I have a lot of experience with them. I would make a simple base with 2 by 4s and then a simple swivel (can be as simple as a bolt) then like another 2 by 4 or a 1 by 4 for the gun to strapped to

Could you describe the trigger setup more clearly? My impression is that the 1/4" quick connect is in the fill port of the QEV, and you have the female end connected to the hose, and to the blowgun. I think, based on your description, however, that your problem might be a combination of 2 things. One, you might be restricting flow with the small I.D. hose, and two, you might simply have too large of a pilot volume for the blowgun to exhaust, especcially if your hose is long. If you could clarify some more, I'd be happy to help

Wow that cannon looks brutal.
The flanges with the bolts give it an awesome look.

I do understand it is not very easy to walk around with, so you should indeed try to make a stand for it, preferably a wheeled one.

Drop as much of that hose as you can, because this is an unbelievable amount of pilot volume and flow restriction that you are adding up.
Make sure to do that quickly before some "efficiency maniac" reads this topic and is going to scream that you should cut it.

Jesus H. Christ, love the look As above, a (much!) shorter trigger line will greatly reduce the QEV's pilot volume and therefore it should fire well.

This thing looks like it can do a LOT of damage, even at low pressures - so pictures/videos would be much appreciated

I personally do not think the long hose will have a great effect on the actuation speed. The pilot line is only hooked up to the QEV, not the big valve. As a result, the drop in performance will not be anything near as great as if you had a hose leading from the launcher to the main activation QEV.

This cannon does look like a monster though; those big flanges must have cost a fortune!

Now that thing has some cohones... I like it!!

Recoil is going to depend on the mass of the projectile you fire. I assume with a 3" barrel you'll be shooting baseballs and veggies cans...these (esp the veggie cans) will produce a very noticeable recoil wallop.

You're going to need a fairly sturdy setup as you have already surmised. The quickest route would be to mock up a 2 x 4 mount. Here's an A frame type I've used.

It has no recoil comp but you could certainly build it in to it. It was orginally a trebuchet frame... 8)

Recoil could possibly be damped with a pneumatic hood lifter. You can get those at an auto parts store. They come in different sizes and forces so you will have to experiment a bit to get one that fits your need.

Looks great! Work on improving the triggering as others have wisely suggested.

It looks like Frankenburstdiscs' ungodly great big brother
I hope you used pressure rated BOLTS, lol.
Great work mate, can you hurry up and fire this beast please, oh a video of said action is a must too

It looks... BIG.

How much has this project cost you? Those flanges and even the pipe itself must have cost a pretty penny.

Looks good, always great to see something taken to a larger than normal scale. A vid would be nice...

Just taking another look here....love the bolts man! and the flange usage. Very inventive!

I know it's heavy...love the bolts though!


PS. Did I mention I really love the whole 6" flange bolt thing you have there.....??? You need to put this dog up for stud service man.... ...seriously....

^I think I need a paper towel^

absolutely Gorgeous.... and HUGE! and the flanges are awsome.

How much did you spend on that bad-ass mother F***er of a cannon?

for a stand idea
http://www.spudfiles.com/forums/new-pne ... 14897.html

Took the trigger hose and cut it much much shorter, works great now. Just took it down to the field, mounted on the track rack. The ranger worked as a pretty decent stand, so now we just need to build a simple elevation and windage adjustment. Took some video, and more pictures, ill see if i can figure out how to get video up.

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Everyone loves flange it would seem

....Loves flange!!

Were these dry fires or did you actually shoot a projectile?

@JSR: what's up with your discombobulated link...