[Sachiel7]

Thanks for the input. I would also like to know how pnuematics could be integrated as actuators for the arm. Our arm is not currently planned to be strikingly large, but large enough to go from the top pivot mounted near the back of our bot at around 4.75 to 4.5' high (from ground level), to around 8-9' high at the end upon raising (including the height of our assembly on the end). There are two things I wanted to address: Counter Balancing. We're hoping to counterbalance the arm (from the actuation point) to eliminate most of the load except the tetra. Also, we're only looking at manipulating one tetra at a time. On top of all that, we hope to use pneumatics to provide our actuation. The point of actuation will likely not be located right at the 4.75' mount for the bar, but closer to the center, no farther than 2/3 of our arm's length from the end.
SO (*huff huff*) With all that said,
Roughly, what kind of equations can I use to get an idea of what kind of load I'm talking about here? We still aren't 100% determined for our Grabber, so the sizes aren't set, But, lets assume our Tetra Manipluator is 1' long in from the front of our bot. We're utilizing the 38" for our front-back dimension. If we're mounting the Supports for the pivots about 5-6" off the ground, the pivot for the arm is roughly 4' from our chassis. Running through the math, our arm sections would be roughly 4.5' long, or less. So, we'd acheive a heigth of around 8 ft. or so.
My question is, lets say we mount a piston 18" out from the pivot (I'd probably make it more) to supply our upward force on the lower of the pivoting bars. If I used a Piston (or 2 pistons, one on each side) Roughly how many lbs of force am I looking at pushing? Do I just add up the weight of all the items being raised? I'm referring to the Pneumatics Manual, p. 12/19. The talbe lists the extend and retract forces of the pistons in pounds. So, if our arm weighs 30lbs plus tetra, (I'm just pulling out of the air, I'm not sure how much our design will weigh) would it be safe to assume one could use a piston with 40+ pounds of force extended?
My Guess would go something like this:
There is 48" from the point of Actuaction to the end of the arm, where the 10 lbs of tetra is sitting. This gives me roughly 480 in lbs. How does that translate into Pneumatics?
I think I may be getting a few units or my math mixed up (It's been a REALLY long day)
But I'd like an idea of what kind of pneumatics could be integrated.