SpudFiles

Does anyone think it is in anyway possible to mod the solinoid in a sprinkler valve to make it open simontaniosly, instead of the slow way they are built so that it doesn't cause water hammer in the PVC?

Most people who mod their valves remove to solenoid and rig it to actuate pneumatically. But as for modding the solenoid itself, I don't know of any way myself.

I know about the other way were you mod the valve to do the blow gun and stuff, I was just wodering about this.

i suppose if you blocked the equalization hole then filled the valve from the pilot side then filled the chamber you could get a bit more performance. maybe use a check valve instead of having to fill the chamber and pilot separately. increasing the size of the tube the air exits the pilot through would also increase performance

Hi,

Alternatively, look for a bigger/better/faster solenoid valve and use that.... I have one for a washing machine water inlet. It proved hopeless as a gun main valve, but it might be OK as a trigger. Remember to get one for the desired voltage, or be prepared for boring coil rewinding.

Regards
Soren

You can mod most solenoid operated valves to work somewhat better.

The first thing to do is to disassemble the valve, then remove the solenoid from the valve top plate. Drill out the hole to whatever you think you can get away with and still have the solenoid seat properly. If you can double the diameter of the whole you would have 4X the flow through the solenoid and the diaphragm will open faster.

Try to trace where the air goes after it exits the hole. Any other places that restrict the air flow?

You could try to mod the electrical system to get the solenoid to cycle faster. Easiest thing is to make sure you have plenty of current from your batteries. A single 9V will cycle the valve but it might be a bit faster if you had the correct voltage (12V or 24V typically) and more current. A pair of 9V's in series will put at 5 Amps or so if the batteries are fresh. The current will drop pretty quickly as the batteries wear out. To offset the drop in voltage as the batteries age, you might try wiring a photocap (~120uF, 300V cap from a disposable camera) across the batteries. The photocap will charge to 18V (for two 9Vs in series) then dump that charge very quickly when you pull the trigger. You really only need a cap rated to 30V or so but the nice thing about the photocap is that they have very low internal resistance and will dump their charge in much less than 1 millisecond. The solenoid is an inductor so it will stretch the discharge time somewhat but that happens with the batteries as well.

o yea one thing i forgot to mention remove the spring, they serve no purpose, its only in there to help the valve close once the solenoid is turned off but in a pneumatic re sealing the valve is not a requirement (ok so as you bring the gun up to pressure a little air will leak down the barrel but it will seal the valve completely withing 3 seconds)

singularity wrote:o yea one thing i forgot to mention remove the spring, they serve no purpose, its only in there to help the valve close once the solenoid is turned off but in a pneumatic re sealing the valve is not a requirement (ok so as you bring the gun up to pressure a little air will leak down the barrel but it will seal the valve completely withing 3 seconds)

The spring is so weak that it doesn't have any impact on performance. Leave it in for reliability.