at 100psi, it does not open with 9volts, 12 volts makes it honk throughout the whole release, as if its not opening all the way (But i dont know if that is possible) So i guess voltage is my problem... I'll try it out when i get a chance

Yes my valve is similar to that one, made by rainbird, different color, but exactly the same otherwise

I considered the voltage, but it was a steady long honk (like 4, 5 seconds)... Meaning the solenoid was triggered the whole time... aren't those things basically either on or off?

I'll try upping ...

I just bought a new valve, and it honks like crazy. I thought it was cause it wasnt opening all the way, but i read the trouble shooting and it says the pilot valve is too small... opened it up and confirmed that the hole is really tiny.

Is it possible to make it wider and still use the solenoid ...

so i gotta try increasing the length of my barrel to see the difference haha

100psi with a 90gram projectile (2 inch by 1.5 inch potato)
(3.53 in^3 X 15.4 g/in^3 = 54 grams) 54 grams seemed to light, so i upped it to 90,
but at 54 grams it says 360fps
and for 90 grams it says 280 fps
i guess a 2 inch by 1.5 inch potato would weigh ~54 grams

Ok, i think i got it now

results are interesting, says i am getting 275ft/s ( my guess was 250-300), so i think i did well..

what is interesting, when i double my barrel length from 25inches to 50 inches it goes to about 360f/s

and when i double that, to 100 inches... it says 450f/s
200" -> 500f ...

theregoesthewindow wrote:[rant]Look in the linkin BLB's post! People put links in thier posts for a reason![/rant]

I did look at his link, and it answered most of my questions... for some it just didnt explain it enough and/or they are values that i have no idea how to figure out, and thats why i posted that

I was unsure about some of the inputs

Piston Diameter is unclear, i dont know what to put there,

Flow Coef i put 30 (my sprinkler valve says Flow Range: 0.25-30 GPM)

Vent diameter i put .1 inch... i am assuming that isthe little metal piece on the bottom of the actual solenoid that retracts when ...

wow, this program looks really useful... if i knew what i was doing

looking at it, some questions

under Reservoir Data

what is outer diam(eter)
and inner diam(eter)

i would assume it is the diameter of my tank, but i dont understand how outer diameter would affect volume of air, so it must be ...

any estimations?

windows were on an abandon house, air conditioners too... they knocked the house down a week later, and i knew they would. Actually only hit the air conditioners once, didnt do anything, they are industrial metal boxes. undershooting hits the brick house, overshooting goes over the park and into the ...

I built my own pneumatic potato cannon with solenoid valve with 9v battery launch trigger thing

tank is about 20 inches long of 3" pipe
I fill usually to 100psi with a bike pump(although i have gone to 160, yeah i know, not smart[but good exercise])
barrel is 1.5 inches, and i use the cheapest ...