Hydraulic pneumatic questions!

[maddox10]

I don't know how paintball regs handle the liquid CO2. Never used them.

But for most pneumatic setups, a decent buffertank (3 times the volume used by the setup) is a good addition.

[Liftoff]

I used a cheap china paintball reg and it worked ok, it will handle Co2 fine ( its a purpose built reg to run on Co2).
I was going for this: http://www.rap4uk.com/MYTH-P3-3000ps...r-p/g-2428.htm before I opted for a full pressure system. Its adjustable to 19bar lowest. Low flow of the reg is not an issue as you anyway need a buffer tank..., now it does not matter if the buffer takes two seconds to fill, whats important is how fast you're going to empty it if you're building a flipper.
As for bottles you could use paintball stuff, there are different sizes to chose from.

[Andron4000]

That's great, thank you.

I would imagine that the paintball stuff is fine, the rules just state appropriate design, specification and certification.
Paintball equipment should satisfy all of these?

Most of the components we use have an operating pressure, and a published proof pressure.
For instance, Festo cylinders are rated to 10 bar operating pressure, but 15 proof pressure.
Am I required to stay within operating pressures, or is the published proof pressure enough to show they are rated/ tested to maximum pressures in that part of the system?

I just do not want to design and build something that will not be able to compete.


I have done a quick sketch of the circuit components.
circuit 1.png

Does the dump valve empty the whole system (including co2 tank?)

[emisnug]

Paintball regulators will be able to handle liquid CO2 for a while, although I'd recommend avoiding the Ninja Pro V2, as the ball inside can freeze up and cause no end of havoc - this has happened to me while playing, I had to wait around 5 minutes for it to warm back up before putting a new 12g in. The Myth G2's (linked above) are ok, but have a tendency to not entirely screw into EU spec bottles.

I would recommend the Sly HP regulators - you'll get around 800PSI output (55ish bar?) (although I'm not too sure if you can get them anymore, paintball politics n'all means that Sly are now a subsidiary of Valken). If Sly don't make HPRs any more, you can get high & low pressure kits for PMI regulators.

For a system dump valve, look no further than the Planet Eclipse POPS ASA - they're well designed for purging the system completely, and I'm sure that Jack (the designer) would love to see them used on 'bots.

[Andron4000]

Thank you. Does the dump valve empty the main tank too?
I think 55 bar might be too much if i run a low pressure system, but i have seen a few that can supply 10-16bar to my buffer tank
i am not too worried about fittings as i can get these turned up to fit.

[emisnug]

No, that purge valve will only take pressure out of hoses and any connected buffer tanks, but will keep pressure in the main tank.

[Liftoff]

Co2 adjustable tank regulators are difficult to find, HP air regs might work, construction is similar to Co2 reg.
You'll need a Co2 tank, a regulator ( HP burst disc is integrated in it) on/off valve, quarter turn valve (vent), safety valve (PRV) set at the lowest pressure your components can handle ( your operating press). Then you'll need a buffer tank, solenoid valve probably a QEV and some fitings and piping.
Have a look at this thread for more info on LP pneumatics:
http://www.fightingrobots.co.uk/thre...hlight=Liftoff

[Andron4000]

Thanks Chris
I have found a few lower pressure co2 paintball regulators, but yes, most of the lower pressure paintball stuff is HPA.

I have sent a few messages to clarify the ruling on the 'lowest pressure components can handle'. Is this the regular operating pressure, or the proof pressure?
As soon as i figure this out it will decide if i run a 10bar or 16bar system.
I would obviously prefer 16, as the cylinders are then smaller, lighter and cost less!
As of yet i cannot find a suitable 16bar rated 5/3 solenoid valve to run my cylinders double acting, though i would think they are proofed to~15 if regular use is 10bar

[Liftoff]

'lowest pressure components can handle' I take it to be the rated pressure of a component, ie the operating pressure. And although the rules say so I'm almost sure that most of the custom built rams and valves which are operated above their rated pressure are not independently tested. This issue has been discussed at length a couple of years ago and from what I gathered it seems that the event organizer has the final say, so they might accept a custom built HP system which was not pressure tested if they deem it well built.

As for solenoid valves, most are rated at 8bar but will handle more pressure. It's not going to explode, but it might leak at the end caps where the pilot valve is.