We’re a long way from the Aquanet-powered plastic pipe spud guns of our youth. [smirpab] over on the SpudFiles forum posted a work in progress of an amazing replica AS50 sniper rifle he’s building. This pneumatic cannon goes above and beyond any air-powered rifle we’ve seen with an Arduino that is able to switch between automatic, semi-automatic, and burst modes with an LCD display and a rate of fire control.
The mechanics of [smirpab]’s build are fairly normal for this level of pneumatic gun; it shoots 6mm plastic pellets from a smooth bore barrel with using air compressed to about 10 bar (145 psi). The electronics is where this project really shines, with an Arduino controlling the mode of fire (auto, semi-auto, and a 3-round burst), and the number of rounds per second adjustable with a pot.
A very cool project, and looking at the CAD renders of what [smirpab] completed project will look like, we can’t wait to see this build finished. As always, this build comes with the standard Hackaday “you’ll put your eye out, kid” warning. You can check out a video of [smirpab]’s piston after the break, along with a demo of the Arduino-powered control circuit going through all three firing modes.
[youtube=http://www.youtube.com/watchv=ImzcSCHBpsc&w=470]
[youtube=http://www.youtube.com/watch?v=9JiIHEzi18c&w=470]
STOP USING COMPRESSED AIR IN PVC PIPE!!!
Which this particular build seems to smartly avoid.
Next up: Arduino controlled paintball gun.
Why?
Forgive the spelling error in the name. :)
But seriously, why?
Two words: pressure rating.
The white commercially available PVC pipe you can buy at your local home improvment store is not rated to take the level of static or dynamic pressure compressed air can provide. There is a reason compressed air is found in metal, fiberglas, or carbon-fiber tanks.
PVC shatters into long sharp slivers if overpressured, turning into a sort of pipe bomb. Not the sort of thing to be holding next to your face.
Or you can buy pressure rated PVC (Sch-80 for example) and operate it below rating. And sleeve multiple layers, wrap it with fiberglass etc. It still be easier to work with (and possibly cheaper) than metal.
PVC pipe is rated for water pressure only, not gas pressure, because water does not expand significantly so it doesn’t undergo explosive decompression. The gas pressure ratings for the pipes are significantly less.
Yeah… I’m not seeing any PVC pipe, neither in his gun or the video — looks brass to me.
Uh… Spud gun? Looks like an airsoft gun to me…
Yeah. I expected something like a gas sensor to measure the right amount of propane into a chamber when I read the title.
Same here. I don’t see no ‘taters.
Sick!
Thats a great setup, have dreaming about this:P
Maybe i will dust of my tools and get a QEV and the rest:P
Keep it up:P
I did a control system for a semi-auto combustion gun back around 2K5, using a PIC and ASM.
Was one of my first freelance electronics gigs.
The white commercially available PVC pipe you can buy at your local home improvment store is not rated to take the level of static or dynamic pressure compressed air can provide. There is a reason compressed air is found in metal, fiberglas, or carbon-fiber tanks. <<> you’ve got 150 litres of air that will blow out the pipe and send shrapnels everywhere
Name not require – It’s not true that ‘PVC pipes are not rated to take the level of static or dynamic pressure compressed air can provide’ Pressure is the same (in fact water is MORE problematic due to water hammer effect)
what is different is that water is pretty much incompressible unlike gases. So as soon as the pipe fails and a drop of water leaks out the pressure is lost. If you’ve got a lenght of pipe with 1L of air @ 15 bar in it ->> you’ve got 150 litres of air that will blow out the pipe and send shrapnels everywhere
Have used standard PVC and pushed it to about 150psi multiple times with no problem. An Arduino hybrid potato cannon would be great and obviously not for pvc.