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First build. Need advice on performance

Posted: Sun Oct 20, 2013 12:00 am
by halestormx
Hi guys i have built my fist air powered Nerf mini vortex football launcher.
The build is as follows.
2" end cap
18"x2" PVC chamber
2"-1 1/2" reducer
1 1/2" -1" bushing
and a 1" threaded adapter that goes to an ummodded rainbird valve.
and then the same out to the barrel which is at 16"

so ive pressure tested this cannon at 100psi. and using a series of 9v batteries activaed the solenoid.
at this point is seems like where my troubles are. the airflow seems slow, like its a flow and not a dump of that pressure in the chamber. I believe that this is due to the the electrical solenoid. I am planning on moding this tomorrow btw.
so in this configuration i am maybe getting that football to go about 10-15'.

I guess my ultimate question is whith this set up( but with the modded rainbird valve to pneumatic realease) will i see an increase in performance? or will i need to adjust my build? Im looking to get about 150' range.

look forward to hearing from you guys!

Re: First build. Need advice on performance

Posted: Sun Oct 20, 2013 6:18 am
by jrrdw
Post pictures of it, that is the best way to help discribe your cannon and any issues you are having with it.

Welcome to Spudfiles. :D

Re: First build. Need advice on performance

Posted: Sun Oct 20, 2013 6:52 am
by mark.f
I think you can reasonably expect to see an increase in performance from pneumatically modifying the valve. Most people electrically actuate their sprinkler valves for only a short period of time before deciding to modify them. :P (I remember my very first cannon with its aluminum-foil-on-clothespin switch and 9v's incorrectly wired in parallel with electronically actuated valve...)

Another thing is adequately driving the solenoid, although three 9v's in series should have no problems doing that.

Other than that, there's no real way to increase performance other than changing the valve or increasing pressure, which I wouldn't recommend above 120 PSI for a PVC cannon (with pressure rated parts).

Re: First build. Need advice on performance

Posted: Sun Oct 20, 2013 7:52 am
by jackssmirkingrevenge
I don't think you'll see a big difference in performance by modding the valve. The fact is that it would take four 1" valves to have the same flow as a 2" valve, so you're either going to want a bigger valve, or significantly increase pressure.

Re: First build. Need advice on performance

Posted: Sun Oct 20, 2013 9:11 am
by mark.f
(Or make it combustion.) :P

By the way, is your valve "honking"?

Re: First build. Need advice on performance

Posted: Sun Oct 20, 2013 9:24 am
by jackssmirkingrevenge
mark.f wrote:(Or make it combustion.) :P
Image
By the way, is your valve "honking"?
Image

Re: First build. Need advice on performance

Posted: Sun Oct 20, 2013 10:15 am
by halestormx
Yes the valve was honking!

I'm gonna modify the valve today and see what happens with it. Then if there are still performance issues I will deff take a picture and let you all know what's happening.

Re: First build. Need advice on performance

Posted: Sun Oct 20, 2013 6:35 pm
by halestormx
thanks everyone that helped out on this build!
once i modded that sprinkler valve it was day and night difference. been shooting this thing for about 2 hours now!
i have to say that for my first build it turned out very well. im getting about 200' distance on around 65psi. just fantastic!

so keep in mind i have some more ideas to dress this up a bit. but again thanks everyone that had good info to help me along