First Pneumatic

[flex180]

I am looking to build my first pneumatic some time soon. what i am am thinking is this: a 40mm golf ball gun with a modded sprinkler valve. It will have a 1m long barrel will be an over/under design. I am not sure on the length of the chamber yet, but i want it to be the same diameter as the barrel.

I want to build it sometime this week, so any ideas or help you can offer is greatly appreciated..

[tghhs]

This forums full of ideas, have you looked?

[flex180]

yeah, i have already decided on my design, but what i wanna know is if there is anything that i have left out or any ideas you have to make it better??

[tghhs]

Well there are many things that could make it better. Depends on how complicated you go. Go to the spud wiki and search "GGDT" this tool may help you.

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http://www.spudfiles.com/forums/piston- ... t8157.html

[flex180]

this is mad! one question tho..... if i was to use a 1 inch modded sprinkler to pilot this gun, what would the valve coefficiency, seat diameter, open time, dwell time and dead volume be?

[CS]

First go to GGDT's site, then click on 'design library'. Then "Orbit WaterMaster, 1".

With all that said, below is the list of input parameters that I feel best model the performance of the Orbit 1" WaterMaster. Note that other sprinkler valves should have pretty similar performance, but in all honesty I've not done enough homework on that topic.

Valve Type --- Chamber Seal
# of Valves -- 1
Flow Coef ---- 23%
Seat Diam --- 1.2 in
Dead Vol ----- 3.1 in^3
Piston Diam -- 2.0 in
Piston Mass -- 22 gm
Vent Diam --- .15 in (1)
Pilot Vol ------ 1.1 in^3 (2)