6 replies to this topic

[jwasko]

I recently purchased a 3/4" solenoid-operated sprinkler valve, and I'm having some problems.

I plan to use the sprinkler valve in a multishot homemade, similar to a gun that has two ball valves and two air tanks. In my homemade, the first (rearmost) valve is a ball valve and the front valve (directly connected to the barrel) is an unmodified sprinkler valve. The procedure that I want to have is:

1. Open the ballvalve anf fill both chambers to approximately 70-80 psi

2. Close the ball valve and fire the first shot.

3. Load a new dart and open then close ball valve, thus providing pressure for the second shot.

4. Fire the new dart.

5. Repeat steps 3 and 4 until pressure there isan't enough pressure left for another shot

The problem that I am having is that, when I open the ball valve, the sprinkler valve just lets all of the air out, instead of allowing the firing chamber to be re-pressurized. I have tried opening the ball valve both quickly and slowly/partially, but it makes no difference.

So, do all sprinkler valves have this problem, or is mine broken?

Possible fixes that I have thought of are as follows:

1. Replace the spring in the valve with one that is stronger, thus placing more force on the diaphragm.

2. Modify the sprinkler valve as per the usual means. However, I'd prefer to not do this because I prefer the electrical method of opening the valve as opposed to a blow gun or ball valve.

So, will either of these work? Does anyone have other suggestions? Also, could someone provide a link to a sprinkler valve mod? I've searched through Google and Spudfiles but to no avail.

[WEASEL]

I don't know what brand of solenoid valve you bought but I believe I can help you anyway. If you know how a solenoid valve works then you know that a small amount of air comes from the inlet and goes through a hole in the diaphragm to the top of the valve above the diaphragm. I had a similar problem to yours and i solved it by making that hole bigger. On mine, (it was green, orbit watermaster i believe) i just removed a little piece of plastic that was in the hole(some sort of filter i believe, but its for dirt when using the valve for water so it just restricted airflow). If you don't have this piece of plastic and just a hole you can just make it a little bit bigger, but not too much, trial and error might be a good idea. I hope this solves your problem.

[Pineapple]

Here's the complete how-to, courtesy of Spudfiles, the prime spud-shooter website.


It's a lot harder than it looks working with pneumatics, adopting from the plumbing department to make sprinkler valve cannons. It gets easier with experience.

As far as electrical actuation; my Hunter brand sprinkler valves didn't quite open as quickly or completely as when I modded them with an air dump, namely a blow gun spliced in the diaphragm "top" side of the valve. On top of that, my guns would let out a bellow like a sea lion after chucking my test projectiles 20-30 feet (as opposed to the 200 - 300 feet I had expected). I never found out if increasing the solenoid voltage (I used 12 volts in what I found out later was 24v solenoids) would open them up faster. You might want to experiment there.

Good luck!


-Piney-

[Prometheus]

Here's the complete how-to, courtesy of Spudfiles, the prime spud-shooter website.


It's a lot harder than it looks working with pneumatics, adopting from the plumbing department to make sprinkler valve cannons. It gets easier with experience.

As far as electrical actuation; my Hunter brand sprinkler valves didn't quite open as quickly or completely as when I modded them with an air dump, namely a blow gun spliced in the diaphragm "top" side of the valve. On top of that, my guns would let out a bellow like a sea lion after chucking my test projectiles 20-30 feet (as opposed to the 200 - 300 feet I had expected). I never found out if increasing the solenoid voltage (I used 12 volts in what I found out later was 24v solenoids) would open them up faster. You might want to experiment there.

Good luck!


-Piney-

Well, with electric motors, increasing the voltage increases the speed. So the lack of potential difference might have an effect.

[jwasko]

Thanks for the link, Piney, and the tip, Weasel. I think I have a Rainbird (to lazy to go look right now), but it does have one of those plastic things on the diaphragm. I guess you could call it an air restrictor, eh?

Also, I might as well bring up a bit of a finding as far as unmodified sprinkler valves and barrels for them. Originally, I tested it out with a 9/16" barrel that fits my darts how it should for a compressed air gun (namely, fairly loosely). I got about 5 feet.

Later, just for kicks, I put a piece of 1/2" CPVC on it. Now, this CPVC fits really tightly on my stefans. In fact, it's even tighter than 17/32" brass. Anyway, when I opened the valve, the stefan hit the wall that was about 10 feet away with a fair amount of force. I haven't done an actual range test with that setup yet, but it's got to be at least in the "half-decent" (sp?) range, maybe 40 or 50 feet.

So, in summary, unmodded sprinkler valves seem to work better with a tighter barrel. Perhaps a "telescoping" brass barrel would be even better.

[Prometheus]

If the barrel was too loose, that could explain the poor range. Try 3 9V batteries, as the excess 3V will do no harm (assuming it's a 24V valve). 12V will probably open it too slowly. Also, check you current, as a solenoid ( fancy electromagnet) requires a current, and if it's too weak then it will open slowly.

[jwasko]

If the barrel was too loose, that could explain the poor range. Try 3 9V batteries, as the excess 3V will do no harm (assuming it's a 24V valve). 12V will probably open it too slowly. Also, check you current, as a solenoid ( fancy electromagnet) requires a current, and if it's too weak then it will open slowly.

I do have three 9 Volts wired in series. But how would I check the current? What kind of current should it have?