so your off the shelf pneumatics gear is rated for robotic combat applications?
If not, then all the nice specs on paper don't mean a thing.
Engineers are not perfect, and neither are the things they design.
I wouldn't trust an expensive pneumatics part any more than I'd trust a part I'd built myself and tested thoroughly. (yes the parts in Stealth were quite comprehensively tested before being used in the robot)

How does this $10 purge valve improve the safety of my system?
If there was a forseeable situation in which it would be of benefit I'd gladly fit it. In the mean time, I'm happy to have several less failure points, and some lunch money.

I have heard peoples' bad gauge stories, but the thing that sealed the deal for me was the gauge on my extinguisher bottle blowing the face off and nearly hitting me.
It had not been used in a robot, or under any extreme conditions, but the tube inside the gauge had a leak, which let it pressurise the lens part.
Fortunately it was only <100psi and I wasn't looking into the gauge at the time.
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The Engine Whisperer - fixer of things

You have very good logic.

"The rules are only for people you want to obay them"

Do the rules define a particular purge valve?

Is it PurgeValve™ or just purge valve?

what is wrong with a quick turn on the CO2 tank in my bot acting as a full cut off as well as a (secondary) purge valve?
The system is purged already unless it's stuck on somehow, in which case it'll be out of gas in a short time anyway.

Can you see that the rules are written around a set of assumptions, and my bot doesn't fit into the preconceived ideas of a pneumatic system?

I don't ignore the rules, but I won't build my bot the same way everyone else has just because those who wrote the rules have no imagination.
There's more to design than engineering, and every good design has some imagination and lateral thinking applied to it.

If there's a bot sitting there hissing and leaking, would you go and turn off a valve, or just let it run out of gas?
I think I'd rather let it sit there and sort itself out if there's a potentially damaged cylinder sitting there safely venting with no person to injure.
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The Engine Whisperer - fixer of things

Last edited by DumHed on Mon Sep 18, 2006 4:22 pm; edited 1 time in total

One bot pulses a tiny bit of gas into a large ram with big exhaust ports at the end of its travel.
This ram works directly on the flipper ie 1 to 1.
None of the gas is stored anywhere in the system to need any gauges or purge valves.
I haven’t time to describe your system, work to do but you but it is very different.

quote:

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Originally posted by Rotwang:
One bot pulses a tiny bit of gas into a large ram with big exhaust ports at the end of its travel.
This ram works directly on the flipper ie 1 to 1.
None of the gas is stored anywhere in the system to need any gauges or purge valves.

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All this talk about the rules, what exactly makes Stealth unsafe?

Not how it does not comply to the rules......

no buffer makes a fairly large difference.
There is no constantly pressurised system in the bot which needs monitoring, or has extra fittings and hoses that can fail.

The tank, due to the liquid storage of CO2, is either full or empty from a pressure point of view (in general).
the rest of the system is only under pressure during firing (even the valve body), and that only happens in the arena.
It's actually much safer than a bot where you're pressurising some of its systems while sitting next to it.
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The Engine Whisperer - fixer of things

There can be no comparison regarding safety for a closed pneumatic system compared to an open pneumatic system. The only common denominator is the tank.
Especially when one is using low pressures <100psi and the other >100psi (more than likely 250psi for a pneumatic launcher) this excludes the tank.

There are safety item that need to be addressed for both setups but need to be addressed differently. For the simple reason of the designs are different.

For a closed system, yes a shut off value and bleed valve, etc, etc is needed.
As at all times when air is on there is part of the system that is pressurized when sitting idle. (Excluding the tank)

But Stealth’s system is an open port system. In other words the only point of high pressure is in the tank. The rest is vented and there is no pressure present in the system when sitting idle.

Another thing is that a soda stream system regulates the output pressure and flow to make it safe for a domestic use. (not sure of spec) I could not imagine it outputting at the max tank pressure for a domestic use. Simple fact of safety
I do believe that this would pass Australia regulations if it did.


With, should the tank be full or not at weigh in.

I think it would be unfair for everyone else if it was not a full tank at weigh in.
Just because the co2 is vented during the match doesn’t mean that it should not be counted as weigh.

The more mass spinners and ram bots have to hit the more self inflicting damage occurs due to extra mass. Even thou it is only 600g about. This would increases the self inflicting damage considerably. (I haven’t don the calcs)


You choice to build a Flipper (High powered flipper,)
I choice to build a spinner (High powered spinner)

In both robots there are
Drive train, wheels, speed controller, battery pack for drive, frame,

Then you install pneumatic cylinder, solenoids, regulator, tubing, fitting etc, control cct, co2 tank

I install mag motor, weapon bar, clutch, solenoid, wiring, heavy duty switch, control cct, extra battery packs

Now to get the pneumatics to work, you need co2.
To get a mag motor weapon to work you need extra batteries.

If there is a weight bonus for extra co2 why shouldn’t there be a weight bonus for extra batteries.

It comes down to PRO’s and CON’s for weapon choice.

Vented gas reducing weight during a match is a CON
Extra batteries to run a weapon is a CON

Throwing a robot 4 feet in the air is a PRO
Spinning a 2 x 500g ball of steel at 3000 rpm within 1.5 sec is a PRO

Reduced armor for both types of robots is a CON


This is the sport, pro’s and con’s for different designs.

To get a more powerful weapon something else must be reduced.


And for a different design then the EO’s are the ones that make a decision.

Therefore if you don’t want to have the gas weight counted become an EO
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It's all about the destruction.

CO2 assisted spinner 600g free weapon mass w00t.
put 2x 300g tanks on the tips and a pinhole in the back to "spin it up"
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Mechanical engineers build weapons, civil engineers build targets

now that would be a Hoot
but does have some safety issues
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It's all about the destruction.

quote:

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Originally posted by Daniel:


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Originally posted by prong:
The poll has already spoken..... The builders have decided!
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So you have said in four posts, but not a compelling argument.

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I hav e had enough.
If you all want to ignore the internationaly accepted rules then go ahead.
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Get Some!!!

Secretary of the Queensland Robotics Sports Club inc.

You might get the last laugh yet if the RFL does go for the FRA pneumatic rules but that is going to be a hot potato.

I don't think the US guys will care much because they nearly all run HPA which weighs bugger all...

Hoorah, after 9 pages, with a lot gas vented, we can close this thread. Shall we weigh the debators before the debate or after, so see if they lost weight after the battle
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https://www.halfdonethings.com/

Just wondering Aaron, do you think that link I posted earlier might have led Nick to that other Forum.