I am wondering how people build air cannons that seemingly have no air refilling time. Here's a couple videos showing some of them. https://www.youtube.com/watch?v=75osjenPLWw https://www.youtube.com/watch?v=3PJIiQ3tkIc I don't see any air compressor anywhere, not even a large noticeable air tank l...

Are QEVs available also to 30 bar?

It might be - but the labor associated with making a custom piston valve isn't worth it. I'll have enough work with the whole metal gun. And solenoid valve is able to push a lightweight projectile at reasonable speeds from 2L air reservoir even in this setup (around 70 m/s2 which for this tank gun e...

It is unusual to answer your own topic - top-quality solenoid valves are the only reasonable options. It depends on the length of a barrel whether two smaller but faster valves or one bigger and slower valve are alright.

Hey all, I'm gonna need to build a system with 75 mm caliber barrel of 3.5 m length. The installation space in a tank turret will be very limited, thus I cannot go with a huge and low pressure chamber. All will be steel-made. The expansion chamber is expected to be around 3-4 litres and hold up to 3...

Good advise! I didn't know such things exist. So far I had an idea with two to three regulators set to different pressures and regular safety valves behind them.

Hey guys. I'm using a heavy paintball AT gun powered by HPA ranging from 9-14 bar (depending on the shooting distance). It does currently have a standard regulator with two gauges on the scuba bottle. But anytime shooting distance suddenly changes (which happens often), I need to adjust the pressure...

You are my hero, Jack! Thank you

Does anyone have a GGDT installler/exe file? I lost it on the old PC and now I would like to make some compressed-air mortar calculations. This tool was so handy!

Hi guys, I finally tried GGDT and it is really useful tool. If nothing else I was able to calculate the drag coefficient of my shots based on that :) Is there a way to calculate the velocity at a distance? Like I would like to calculate a velocity drop after 50 meters, can I do that inside the tool?...

The performance itself may not be that big of a trouble, but as you mentioned before the effect has to be at least somewhat believable. Regarding your concerns: - the system is under pressure for a brief moment only (and it is not exactly air tight in the breech area either). That's why I wanted the...

Ok, here is how the setup looks like.

Just to make sure I got it correctly, Ragnarok: by tapping gas off the barrel you mean to put something like a T-piece in the hose that currently leads the air into the barrel and connect in to the cylinder? Or something more elaborate? The air discharge is very quick but the cylinder needs the pres...

Here is my simple drawing. What I have in mind is a modified pneumatic cylinder with an exhaust. Upon opening the valve the cylinder pushes the barrel-breech assembly backwards for a moment. Then the piston reaches the exhaust and the air rushes to the barrel to make the shot. Piston then travels fu...

Thanks guys! The launcher is so heavy and made of steel only for realistic look and feel. And I'm afraid I can't make the shot heavier even in the form of extra dispensable flour. These parameters are constants limiting the amount of remaining options. That being said, Ragnarok is right about the mi...