Some of the heavies use an accumulator bladder.
Others have used a pneumatic ram, the piston just follows the oil.
Heard about 1 using an 8" inner biketyre.
Some of the heavies use an accumulator bladder.
Others have used a pneumatic ram, the piston just follows the oil.
Heard about 1 using an 8" inner biketyre.
Now that I have my idea all modeled up with the hydralic cylinders in place, I think I'm leaning more towards the idea of a low pressure (16bar) system.
I am worried about the hydraulic components being quite heavy and expensive, as well as the forces from the hydraulic cylinders self destructing with reactant forces.
I'm also concerned about freezing, as the port sizes seem relatively small for a full pressure system, and I don't really want to get into re-certification for modified parts where possible.
I can use a 50bar fire extinguisher co2 tank, or possibly this if it's allowed?
http://www.workshopping.co.uk/produc...LiEaAj_B8P8HAQ
...Through a regulator, (which I am struggling to source. BOC have quoted £280 for one)
into a 16bar low pressure buffer tank.
This should combat freezing and also the reduced force may mean I don't tear myself apart
In regards to the actuator, Norgen cylinders have an operating range up to 16 bar,and an 80 bore cylinder from norgen weighs less than a 60bore hydraulic cylinder.
Festo and SMC cylinders would be much cheaper to me as we use them all the time at work, however their operating pressure is 10bar I think, thought they are tested to 15.
edit: (Just had a check, they are proof tested to 15bar, fittings to 30bar, is this ok to use at 15 bar or do we need to stay at operating pressure?)
I am sure they are capable of taking the forces, where would I get these tested/ certified to stay within the rules?
We do CE mark at work, and use a lot of pneumatics.
With the low pressure system I should be able to use pretty standard pneumatic valves/ fittings/ lines
I get about 740kg running high pressure, and 400kgf with low pressure but much less risk and less self destructive.
Last edited by Andron4000; 13th December 2016 at 11:13.
Regulators go for paintball stuff, there are shimable ones which you can adjust to your required pressure. I doubt you'll be able to find any compact solenoid valves rated 16 bar tho, that said I have successfully used a 10 bar rated 1/8 bsp ported solenoid valve with pressures in the range of 16bar, after sealing the endacaps, because thats from where they leak...don't ask me about certification tho
Take care.
Normal pneumatic regulators that can regulate 70bar+ to 8 - 16 bar cannot handle liquid CO2.
Paintball regulators have a very low flow, and don't fit on Industrial CO2 bottles.
Can the paintball regulators handle liquid co2? Could the low flow rate be combatted with a reasonable sized buffer tank?
if not, does anyone want to sell me some pneumatic stuff?? í ½í¹‚
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.
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.
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?)
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.
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.
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