Trev ......Chad is U.S. based.
http://www.mcmaster.com/http://www.mcmaster.com/ is probably better.
(Message edited by woody on September 29, 2005)
Trev ......Chad is U.S. based.
http://www.mcmaster.com/http://www.mcmaster.com/ is probably better.
(Message edited by woody on September 29, 2005)
I have been looking at the numbers from other pneu bots (in the US)...
So here they are
Judge: 60,319 lb-inches
Ziggy: 56,549 lb-in
Bounty Hunter: 84647 lb-in
So if I scale that down to a 30lb bot, That would put me in the 5000 lb-in range.
So, now I narrow my question... What do I have to do to get 5000 lb-in? (at the tip of my arm). The bot will use a 4 bar system, not the usual cylinder in the front, arm mounted at the back.
~Chad
Whats a low pressure for a feather flipper. I was thinking of 100-150psi. How long would it take to flip a 12kg robot at 100psi forward?
Or if not 5000lb (might be to high of a goal), then enough to launch a bot 8 high Or tip over a bot double its weight... Large goals, I know.
~Chad
Heres some quick calculations I just did out of interest:
5000lb-in is approximately equivalent to a ram with a swept volume of 33cubic inches at 150psi. This is approximately equivalent to a 3 bore and 5 stroke.
5000lb-in is also equivalent to a 30lb robot, 167 high (14 feet or 4.1m).
But from the crude analysis other people have done on Wheely Big Cheese, Gravity and Chaos 2, you can only get an efficiency of about 50%, so in reality if you put in 5000lb-in, the other robot will go about 7 high.
I think LP systems are typically more efficient than HP but I dont have any real experience or data to support this. Im sure a 4bar system will be less efficient than a basic rear hinged flipper.
So in actual fact your aim of 8 is more ambitious than 5000lb-in.
So two 1.5 x 6 rams may be nearly adequate.
Mario is probably the best person to advise you on this though.
Fairly meaningless figures without a time constant.
But lets work on the assumption that you supply your 5000 lb-in effectively .......so thats 416 lb-ft .........your chucking a 30lb bot
416 divided by 30 ......thats close to 14 feet
then assume 50% efficiency ...7 feet of potential throw.
A 2 bore ram with a stroke of 8 running @ 200 psi matches your throwing requirements and would produce 628 lbs of lift ......more than satisfying your last requirement.
So its a question of matching up a decent size ram with a valve that will flow enough to fill it in a VERY short time..... i.e. tenths of a second.
I believe that a valve and pipework with a Cv of 5 or more together with the 2x8 ram would do the trick.
Seems Mark beat me to it .........
(Message edited by woody on September 29, 2005)
Its nice to know we both got the same numbers independently though!
@ Mark
Yep .....a perfect match
(Message edited by woody on September 30, 2005)
Chad .......How much wieght can you dedicate to the pneumatic ssetup?
I would like to keep it around 10 pounds if possible, but as everybody knows... Less is better. 10 would still give me weight for a half good frame and some ok armor. Their are some 30lb spinners that are just crazy with the amount of energy they pack! But I think it would be good to see them flying about 5 in the air
Bookmarks