SpudFiles

Well I just got back from playing with my cannon. It was indoors so I was limited on my ammo choices..... Sorry that I don't have any pictures yet, the cannon is still at the building I was playing in.

This is with an unmodified sprinkler valve.

The mid sized nerf darts flew around 100 feet with a barrel angle somewhere between 20 and 35 degrees. Ping pong balls flew around 75 feet.

I know a better valve should get me more power because I am only dropping the air pressure in the tanks by about 20-40PSI (from around 100-125PSI).

GGDT says my range with a marble should be around 800 feet in theory with a modified sprinkler valve.



The recoil was fairly significant with the 1 1/2 barrel. I was using the air compressor itself as the backstop (nothing else with enough weight) and it moved back 2-3 inches. This is a small 3 gallon craftsman air compressor from sears. I have the material for a 3" barrel but I ran out of PVC primer (due to a spill, luckily onto paper towels)

So...

...You were <b>indoors</b>, but had <b>100</b> feet of space
...unmodified sprinkler valve
... mid-sized nerf darts
... <b> Ping pong balls</b>

The recoil was fairly significant... 3 gallon craftsman air compressor... it moved back 2-3 inches

I needed a good laugh this morning, so thanks!

I think I'm gonna fire up my nitromethane-injected rubber band machinegun and take out that annoying block wall in my back yard.

Sounds cool. I'm not sure about the 3 gallon compressor moving from the recoil though.

Whats the size of your cannon? Have any specs so far? Pictures would be great asap.

The op lacks a lot of information about the canon.

Valve and chamber sizes for example.

While the projectiles are very light, it is possible for a volume of air to produce recoil/thrust. (A large volume to be sure. )

100 feet indoors is not that hard to come by. A barn or warehouse can easily be 100 feet in length or more. The hog barn on the farm where I grew up, was 200 feet in length.

More infomation is required.

I'm also left wondering "What was the point of the OP?"

The original post is the result of posting at 3AM.....

Chamber Diameter: 4"
Chamber Length: 2x 5'

Valve: 1" Unmodified sprinkler valve

Valve Control: Small electronic control box with two switches and an LED. The first switch is a DPDT toggle switch that turns on the LED and allows power to flow to the second switch. The second switch is a monetary push button switch to actually activate the sprinkler valve. The control box powers the LED with 2x AAA batteries and the sprinker valve with 3x 9v batteries

Barrel: Interchangeable barrels, I tried 1/2" and 1 1/2" last night.

Pressures used: up to 125PSI

Pictures would be nice, when it comes to describing pressures, chamber and barrel diameters, you can basically describe 25 percent of the guns here with one go. Sounds decent though, but an unmodified sprinkler valve? isn't the power supply a bit of a burden? You're already using the compressor, why have another power dependant device when the modified ones are just as effective, and require no more than a blowgun valve and sometimes some hose?

I am going to be modifying the sprinkler valve as soon as I get the parts .

What I'm wondering is why have seperate batteries for the LED?

Eh, it is just parts I had available at the time.... The LED assembly was only rated for 2-3 volts

Edit: and sorry, I know this should probably be in the showcase forum not this one.... I would have pictures today but I slept the entire day due to limited sleep the two days before.

jared555 wrote:Eh, it is just parts I had available at the time.... The LED assembly was only rated for 2-3 volts

With the right value limiting resistor, you can easily run your LEDs with your 3-9v sprinkler actuate batteries. Try a 1k - 1.5k ohm 1/2 watt resistor in series with each LED....

I don't feel like desoldering but next time I do an electronic project I will

...

TurboSuper wrote:...

And your point in posting this message is? If it is because of the 'I don't feel like desoldering' comment.... it works and removing the solder without just cutting wires would take quite a bit of time and also risk overheating the LED