Pneumatic questions, sorry!

**Max** · 19th July 2011, 10:26

I am just starting to think about my next robot and like the idea of a featherweight pneumatic flipper. I have read through a lot of the old threads but am still left with some questions. I still don't understand what the stroke and the bore mean? Also I remember seeing a link to a great website on pneumatics in combat robotics but I can't find the link, does anyone know what it was? I was also wondering if you realy need a buffer tank because due to my design i can only fit in either 1 main tank and 1 buffertank or 2 main tanks which i think i will need to get plenty of flips(i am thinking of
Using p16oz paint ball gun bottles) I am sure that more questions will follow soon but thanks for now.

**Laser** · 19th July 2011, 10:39

Stroke = how much the ram goes up and down
Bore = what the diametre of the inside of the cylinder is.
website = http://www.teamonslaught.fsnet.co.uk/co2_info.htm
go to an event ask around about pneumatics, thats how I learnt

**billy breach** · 19th July 2011, 10:41

I think stroke - is the travel distance of the piston
I think the Bore is the diameter of the cylinder - this is important for working the power of your flipper etc.
I would say a buffer tank is needed as it will feed your 5/2 valve quickly and allow your piston to stroke.

LINK http://www.teamdavinci.com/understanding_pneumatics.htm

edit - someone can type faster than me

**Max** · 19th July 2011, 10:55

Thanks for the super quick responses guys! Both of those websites look great i will have a look at them tonight. Another couple of questions, what's the difference between an fp and a hp system. Also if you are using fb am I right in thinking that you don't need a regulator?

**Laser** · 19th July 2011, 11:30

Originally Posted by Max

Another couple of questions, what's the difference between an fp and a hp system.]

Nothing they are both the same.

Originally Posted by Max

Also if you are using fb am I right in thinking that you don't need a regulator?

Yes you are right.

Also you may want to bear this in mind, these pressure levels (fp) are very high which are very dangerous.
Its best to start off with low pressure (LP) and then work your way up.

**Max** · 19th July 2011, 12:47

Sorry even more questions, if I was using a fp system then would I need a buffer tank as all the pressure is released instantly (no regulator)?

**Laser** · 19th July 2011, 12:52

Yes.

**Anttazz** · 19th July 2011, 13:16

I'm not the best to answer questions about pneumatics, but don't think you would NEED one, but it would help.

**Mouldy** · 19th July 2011, 13:43

Ideally the volume of your buffer should be atleast 3 times the volume of your pneumatic cylinder

**maddox10** · 19th July 2011, 15:06

Originally Posted by Max

I am just starting to think about my next robot and like the idea of a featherweight pneumatic flipper.

Great, Join the Club.

I have read through a lot of the old threads but am still left with some questions.

Who doesn't?

I still don't understand what the stroke and the bore mean?

Like in combustion engines, bore and stroke are what make up the volume in a cylinder.
Stroke is the distance the piston can travel. Bore is the diameter of the piston (and that is the same as the bore -minus a few 100th of a mm- of the cylinder it travels in). Diameter dictates the surface area. In case of a normal cylinder that is Radius (half diameter) * Radius * Pi (3.14 to be fast).
Surface of piston in cmÂ² * pressure in bar = force in kg.

Also I remember seeing a link to a great website on pneumatics in combat robotics but I can't find the link, does anyone know what it was?

Several websites qualify in that respect.
But for Robot Wars, I have posted these in the past
http://www.dutchrobotgames.nl/index.php ... &Itemid=70
http://www.teamonslaught.fsnet.co.uk/pneumatics.htm

I was also wondering if you really need a buffer tank because due to my design i can only fit in either 1 main tank and 1 buffertank or 2 main tanks which i think i will need to get plenty of flips(i am thinking of
Using p16oz paint ball gun bottles)

Hannibalito III uses a Full Pressure setup, Cutlet/Gravity style with 12 oz main bottle and a buffertank, still we achive 15 flips or better. Amount of flips depends on stored CO2 and volume of cylinder.
I doubt that there is any feather using 32oz CO2.
An option is to use a 16 or 20 oz main bottle and a reasonable buffertank. I aim for 3 times cylindervolume in the buffertank.

I am sure that more questions will follow soon but thanks for now.

Please do.