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Need help with first solinoid launcher

Posted: Tue Dec 04, 2007 10:36 pm
by martyr_maker
Hi everybody im kinda new to spud guns so I was wondering if you guys could give me some advice on one i have been working on for a month or so that shoots out the mini nerf vortex rockets, 2" barrel. The project was intended for use in milsim airsoft so some of the concepts I wanted to have implemented come from that environment of use.

Heres what i have so far:
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Baisically its a sprinkler valve wired to a momentary switch and a 9v battery. The tank in the back is filled with a bike pump to about 100 psi.

When i started this project I intended to have several tanks so that I did not need to carry a bike pump around with me on the field. This was the case with the first launcher i built, basically 2 sections of pvc with a ball valve in the center.
Anyways I built several of these tanks but when I get them screwed into the sprinkler valve and opened most of the air leaks out. That is the first problem i need help with.

The other problem is that it simply does not have the range I need it to have. The ball valve launcher shot a rocket between 75-100 yards, depending on angle. This one is lucky to get half that.

So thats it. Any advice on how to fix those problems would be greatly appreciated.

Posted: Tue Dec 04, 2007 10:42 pm
by ShowNoMercy
First off get rid of that ball valve after the solenoid valve. Then mod the sprinkler valve and maybe increase chamber pressure.

Posted: Tue Dec 04, 2007 10:45 pm
by martyr_maker
ok so then what can i do as far as removable tanks if i ditch the ball valve?

Posted: Tue Dec 04, 2007 10:49 pm
by SpudUke5
Ok well to make the cannon efficient first of all, loose the ball vavle. Just a flow restriction.

Next, mod the valve. That is most likely your reason why you valve is leaking air rather than blasting air. Modding the ball valve will greatly increase your performance depending on the size of the sprinkler valve.

If you have a 1 inch sprinkler valve, it wouldnt be too bad but making a new cannon with a piston valve will give you great performance. The ball valve gives you better performance because it has more flow.

Searching on this website will explain anything else i forgot.

EDIT: all you would have to do is have a CO2 tank or HPA tank and just have a regulator. There is not reason for multiple pvc tanks.

Posted: Tue Dec 04, 2007 10:50 pm
by MrCrowley
Well it's going to be difficult to carry them around anyway.

With a shock pump you should be able to get it up to 80psi in no time, with the mod of the sprinkler valve it will be more powerful and then you should get some decent performance.

And make the barrel a lot bigger, try 2x as long at least.


Oh and I wouldn't recommend a piston valve for this type of application, especially with a bike pump and a cannon of this caliber. If this wasn't for airsoft a piston valve would be nice though.

But don't fret over the piston valve, just make the barrel longer, lose the ball valve, mod the valve and get a decent shock pump.

For the pump, try and get one that pumps out a lot of volume of air, but it only has to go to around 120psi.

Posted: Tue Dec 04, 2007 10:54 pm
by SpudUke5
Oh yea your right, but if he used a regulator and CO2 or HPA, couldnt he then use a piston valve?

Posted: Tue Dec 04, 2007 11:00 pm
by martyr_maker
well the C02 kinda creates a problem for me because most of the airsoft fields dont allow C02 in custom launchers. The only other gas besides compressed air that can be used is HFC134 or "green gas" which is basically propane. Nice thing about air is it is free so i prefer it.

Posted: Tue Dec 04, 2007 11:06 pm
by MrCrowley
LikimysCrotchus5 wrote:Oh yea your right, but if he used a regulator and CO2 or HPA, couldnt he then use a piston valve?
Remember he doesn't want to kill the opposing team, high performance isn't necessary, may as well stick with a manufactured valve too as it's more reliable.

Well you could use propane actually, that'd give you around 90psi depending on tempreature.

Posted: Tue Dec 04, 2007 11:18 pm
by BigGrib
I use co2 when i first start to pressure up a cannon before it's ever fired and use a leak detector on the whole gun to find where it's leaking if you junk that ball valve and mod the sprinkler valve pressure it up sans barrel and drop it in a bathtub full of water and you'll find the leaks in it

Posted: Tue Dec 04, 2007 11:21 pm
by SpudUke5
LOL ok sorry I wasn't trying to create a murder weapon. But propane should be fine. Do you have an ne more plans for another cannon?

Posted: Tue Dec 04, 2007 11:28 pm
by martyr_maker
i was thinking about doing something along the lines of an AT-4 or a LAW sometime after i got all of the bugs worked out of this version. But i haven't put too much thought into it as of now.


Thanks alot guys i really appreciate it. Ill probably start making the changes everybody seemed to agree needed to happen this weekend.

Thanks again!