Pneumatic question.....

is it possible to have a buffer tank too big on a low pressure pneumatic system.

For example, in an extreem case, using a huge air compressor tank on the system powered by a 0.6kg bottle.... what would happen???

Cheers in advance.

JOhn

i suppose the worst thing is not having enough CO2 in the bottle to fill the buffer, which i assume would result in not reaching its full pressure.

Id agree with Alan.

0.6 Kg of Co2 would fill a 30 liter buffer tank to a pressure of around 10 bar... ( anything of a bigger volume would have less than 10 bar ) ...... every ram activation would then reduce the buffer tanks pressure.

A 100mm x 100mm ram ( extend and retract )would use approx 1.5 liters per activation and each shot would have progressively less pressure.

Using a buffer tank of 3 litres for the above setup gives an activation that reduces in pressure from 10 bar to 8 bar as the stroke extends.... then ... a futher reduction in pressure as the ram retracts .........once the cycle is finished the regulator catches up and the pressure in the buffer tank again becomes 10 bar.



(Message edited by woody on January 25, 2006)

thought as much, but wanted to check.

ta

Jonno, I am very worried that you should ask such a question. Now, put my mind and many others at ease and explain what devilish device your planning now. Come on boy! Spill the beans.

Mike.

Arena flipper?
high power trouser press?

Well, primerilly it was for the new arena hammer which was used this weekend, and as predicted needs more flow and a bigger buffertank to give it more of a hit and a rapid fire !!

However, the other reason is as we have so many pneumatics on the arena effects now what with the flipper, hammer, co2 jets, was looking at the possibility of linking it all together with one big buffertank if i add any more....

I do live the idea of a Full pressure trouser press !!!

Dont worry, nothing too major this time.

John
http://www.roamingrobots.co.ukwww.roamingrobots.co.uk

(Message edited by roamingrobots on January 30, 2006)

Has anyone ever thought about the minimum hall size required to run an arena dumping this much CO2 into the air... without the onset of breathing difficulties for everyone?
It might also be worth looking at the environmental imapact we have, as someone is bound to come and get batey with us for dumping lots of co2 into the atmosphere... I seem to remember Derick used argon as a flipper gas, is it dearer, more toxic etc..
just some thoughts, as Im bored at work, theyve upgraded the email server, and badgered up everything...

CO2 is reclaimed from the atmosphere. We cause more damage moving it with our cars.

It will only cause asphyxiation when used in confined, unventilated spaces.

Argon, etc. are much more expensive gases as they are found in lower concentrations in the atmosphere.

A compressor would be a much cheeper, more reliable, safer way of running the arena effects.

Humans breath in oxygen and breath out carbon dioxide, solution get rid of all humans and the earth will be a safer place, :)

I did my treatise on greenhouse gases about 20 years ago, and had had a lively discussion about cow farts as part of the grading..methane being worse than CO2 for atmospheric buggeration..

I reckon the idea of a compressor running the arena effects is sound, and the bonus for jonno would be its cost in the long run... youd be using the venue power instead of your CO2..

back to asphyxation.. a spinner proof arena is a loosely sealed box... say 4 flippers each dump 2x 2kg bottles of gas into it in a fight.. how close are we to getting a bit woozey when we empty the arena? The amount of Oxygen in the space wont have changed but its ratio to CO2 will.. I know CO is more easily absorbed by the blood than O2.. dunno about CO2..

Mike, I fear you are correct - Jonno is clearly conceling something devilish.
One plausable explanation is that the upgrades involve an inscribed pentagonal area, with various lights strobing incantations on the floor and a ram that launches unwary robots as offerings into an dimension of pure pain. Obviously done incorrectly this could cause problems beyond the arena itself and so devices of this kind require great attention to detail...

Does this mean we get to have Buffy at RR events.. sign me up now

The CO2 issue.

Lets imagine we are in a typical event hall. 50 X 30 X 5 meter. This gives me 7500m³.7 500 000 liters

The last time I looked about 150 kg CO2 was used during a typical even.
Each kilo is 512L . 150 * 512= 76800L

Or about 1.1% of the volume of that hall.
Even without any ventilation this wont cause much trouble. Then my farts would be more nasty.

Heres another thought ,there was so much smoke in the arena yesterday I thought I would need patches to overcome the effects,:proud:

well in fairness the arena does have a pollution problem.... lets look at the combination.

1) Co2 used for the flipper, the hammer, and worse of all the Co2 jets.

2) The hazer used now at most events.

3) Pyrotechnics, average 2 per fight.

4) Angle grinders, the new addition, 2 angle grinders, with stu in charge of the button grinding against a M20 nut.

Doesnt sound too good does it. However.... the advantage of the safety net, is just that it is a safety net with small holes in it. This gives us ventilation.

The UK championship arena for August will be a different story as it will be a lot more sealed.
However there is a strong possiblity we will have bull pens, and external activation by then.
I did the farting cow at school... one of the things i remember...... take the average amount ejected x number of cows in the world ... !!!


Food for thought

John
http://www.RoamingRobots.co.ukwww.RoamingRobots.co.uk

(Message edited by roamingrobots on January 30, 2006)

So the small fire inside Bulldog was nothing in comparison,:sad:

Er no............ but the lethal gas that is said to escape from John Bells trousers after a heavy meal the night before far exceeds the volume of gas produced by all the cows in the known universe :)
By volume I mean the amount of gas produced AND the decibel level of the explosion.

I dont see a problem;

The hazer doesnt cause any problems at all, the haze is basically a dense steam, its main ingrediant is some form of glycerine, the same stuff used in cough medicene (so it doesnt make you cough like some people pretend to do, it actually does the reverse!).

With the pyros the amount of smoke given off in the size of venues we attend doesnt pose a problem (at the weekend we averaged 3 shots per show).

And marios calculations above show that co2 isnt a problem, and that was assuming all the gas was released at once, not over 6 hours of shows (not counting how much is released outside during re-filling).

The UK championship arena for August will be a different story as it will be a lot more sealed

Johns right in that this is more of a problem - the Robot Wars arena had a fume extraction system to ensure that the build-up of fumes wasnt dangerous within the arena as with little through-flow of air it was the HSE who raised concerns.

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

It dont help having a trigger happy kid like me on the buttons for the Co2 stuff then does it. Oh dear.

But i fully agree with that Karoline said about John Bell!!!!! LoL!!!

Mr Stu