faster release

[dtengineering]

You have to consider the "bottleneck" in the system. There are some intentional bottlenecks imposed by the FRC rules that are specifically intended to limit the power (and potential hazard) of pneumatics.

One of the bottlenecks is the regulator. To de-bottleneck the regulator, consider putting one or two clippard air reservoir tanks on the low pressure side of the system, in addition to one or two on the high pressure side. That way, when you need 60psi air FAST, you don't have to wait for it to pass through the regulator.

The next bottleneck is the tubing. Consider pneumatic tubing to be similar to electrical wire... shorter runs makes for less resistance. So keep those clippard tanks close to the valves, and keep the valves close to the cylinders.

The valves also present a bottleneck... but you can put them in parallel if you want to debottleneck that stage.

Finally you have a bottleneck at the fitting. Even if you have more valves in parallel than you need, you can only pass air so quickly through the tubing and fitting attached to the cylinder. One way around this is to, as previously mentioned, use multiple smaller cylinders. That way you have many fittings (and many pieces of tubing and possibly many valves) in parallel. Just like a parallel circuit in electronics can deliver a higher current, a parallel circuit in pneumatics can deliver greater air flow.

I also believe there was a Q&A asking if you could use one of the brass couplings to connect a valve directly to the cylinder, which would debottleneck the fitting stage somewhat... but do check the Q&A forums on that. Perhaps a better way to get around that would be to partially retract the cylinder, latch it in place, and then pressurize the cylinder. There is another thread discussing the optimum "precharge" ratio, somewhere between 30-40% sounds about right. This way when you release the latched cylinder the pressurized air is already stored inside the cylinder and has passed by all the bottlenecks. 1726 posted some good photos of their trackball launching design a couple years ago that encouraged us to pursue this route, with good success.

Finally, consider that if you don't need to use air to retract your cylinder, that you can leave one end of the cylinder open to atmosphere. That way there is NO bottleneck on the venting side.

I haven't done calculations to determine which of these is the most significant step, but collectively they all add up to limit the speed that your pneumatics can retract or extend. In our experience using two 3/4" cylinders with latex tubing to improve retraction force (The final design will use 4 3/4"x4" cylinders in parallel, giving us a force equal to that 1 1/2" cylinder, but with four times the air flow rate), we found a significant improvement in performance when using two valves rather than one, and putting a clippard tank immediately upstream of the valves.

Good luck, and have fun,

Jason