Safe Operation

[widow_twanky]

As you've probably read by now I've just picked up the pneumatics for Wheely Big Cheese. I just wanted an opinion from people on the safety of it and compliance with current rules.

The set up is as follows:

Two 2kg bottles (with lever arms) connected to a valve block to the high pressure pilot valves.
A connection to a regulator which then supplies two low pressure 3/2 valves and the dump valves
Low pressure valves supply the pilot for the high pressure valves

To start up the following procedure is followed:

Close dump valve
Remove locking mechanism
Walk out of arena and activate two large servo's which operate the lever arms of the fire extinguishers

(No problems from me so far)

To de-activate the following procedure is followed:

SDe-activate the two servos
Open dump valve

This is where I think the problem is. If the servos fail to operate ort for some reason the valves on the cylinders fail to close then poetentially there is a need to dump 4kg of CO2 through a regulator. Should the regulator freeze then the system remains fully charged.

My question is:

Is this system acceptable with the addition of a high pressure dump valve or do i need to try and get some other form of opening/closing the bottles sorted out?

As far as I can see the way it is done now is perfectly safe as it means that there should never be anything in the system whilst anyopne is in the arena (except to disarm).

Andy

[calumco]

hey, with the lever handles on the bottles, you could drill a whole through them, put a bolt thought it with a wing nut on, so when you want the gas on, squeeze the handle and tighten the wing nut if you get my meaning

[widow_twanky]

hey, with the lever handles on the bottles, you could drill a whole through them, put a bolt thought it with a wing nut on, so when you want the gas on, squeeze the handle and tighten the wing nut if you get my meaning

Not quite as simple as that I'm afraid. They are set up for remote activation and there is no amount of money or sentiment that would get me to shove my hand between the flipper plates of a full pressure flipper and turn on the gas.........................if you get my meaning!!

Andy

[calumco]

im afriad i don't get your meaning lol when you say flipper plates do you mean wheelie big cheeses' actual flipper arm its self? if yh, can't u just lock it open for when you are arming up?- with a length of wood or something then when you've turned the gas on yank it out n step back? if you get my meaning

that should still count as a locking device as it will prevent it from actually moving and harming anyone.

[widow_twanky]

im afriad i don't get your meaning lol when you say flipper plates do you mean wheelie big cheeses' actual flipper arm its self? if yh, can't u just lock it open for when you are arming up?- with a length of wood or something then when you've turned the gas on yank it out n step back? if you get my meaning

that should still count as a locking device as it will prevent it from actually moving and harming anyone.

Callum,

The bottles are accessed underneath the flipper plate. The ram is double acting. This means that if a locking device is used then when the gas is turned on then you cannot take it out because it closes on it. Apart from that I don't really like the idea of relying on a locking device as I see them very much as a last resort.

Probably best I take some photos so it's a bit clearer. To me it seems a perfectly safe if somewhat unusual system.


Andy

[woody]

Any possibility of integrating a manual dump valve into the high pressure feed ...i.e. before the regulator?

Cheers Woody

[gravity]

I wouldnt be really happy with a remote bottle opener actually...

I thought the rules said manually opening and closing of the co2 canisters was mandatory ?


If not, I'm redesigning immediately !

[Mouldy]

WJ is correct- manual opening and closing of the bottles is mandatory. However there has been a rule put in place recently that i put forward at an FRA meeting suggesting the use of a socket on a T-bar as another option (i also had an issue with putting my hand inside a heavyweight to turn the gas on/off)

If you put a bolt through the handles and attach a nut in some way so the bottle can be turned on/off via a long T-bar then there should be no issue aslong as ( i think if i remember correctly) you have one personal T-bar and you make a spair to leave with the arena marshall (so incase of emergency your not hunting around for it)

Many people do vent through the regulators.. i guess it depends on how happy you are with it.. i know on a robot with a rubbish flow regulator it can take quite some time to vent it all.. I would suggest a dump valve on the high pressure side if you can fit it in as woody suggested.

You mayaswell do away with the servo driven idea- it doesnt comply with FRA rules. And it has no advantage that i can see?.. If it fails at the start of the fight you will end up with no gas.. if it fails at the end you will end up dumping the lot.. Even if it does work.. you wont be allowed to use it.

[gravity]

If it fails at the start of the fight you will end up with no gas.. if it fails at the end you will end up dumping the lot.. Even if it does work.. you wont be allowed to use it.

If it fails to close at the end of a battle and another valve fails while you take it out of the arena, it would be even worse...

I know, if if if, but 1 if could cost you your life with a robot of that power !

Using a simple tool, that the security guy also has sounds like a good idea, and I've seen it being used.


I have designed the new robot in such a way, that all the valves etc can be accessed from the side of the robot, so if it does go haywire while activating, at least I'm not in the same action plane as the flipper arm...

[widow_twanky]

Don't really need too much convincing on that anyway. Checked today and can just about get a 12mm threaded rod in throgh the box and with a couple of bolts on the bottle valve can rig it up reasonably safely.

As the valves are hydraulic they have a tendancy to leak so I'll fit in an alpha valve in-line so it can be armed when I want it to be. Just need to make sure there's a dump valve to vent every part of the system.

Andy