So our team was thinking of having a single piston front claw and single piston back claw, both single acting. Would one cylinder of air be sufficient for both to function properly of an entire match or should we buy a second cylinder?
Do the experiment to estimate how many effective actuations you achieve with a single air cylinder*. Write that up well in the engineering notebook, and you will either have evidence that the expense of a second tank* is warranted, or reassurance that you’ll be OK with one. I would expect the anecdotal consensus to be that a second is handy if you can comfortably afford it would allow for the fog of war at events. Generate data using your equipment by your people so you know. Lift drop, lift drop… when does it stop. That doesn’t give you the full story, because some air will leak during pauses and the air temperature will change, but it’ll give you an idea, and you can then run the experiment with a more realistic pattern of deployments over the period of a match.
You can attempt to directly compute how many actuations you’ll get, but the thermal, friction, variation in equipment and so forth make it a thing that would look good in a notebook, but might not drive your decision making in the final analysis.
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We need to be more careful about terminology, to help avoid confusion. The item you refer to as a “piston” is properly called an “air cylinder” to everyone who is familiar with pneumatics in industry. So, to call an “air tank” or “reservoir” a cylinder can be very confusing.
The number of actuations you get from an air cylinder, as previously noted by u89djt, is really up to experiment based on your particular setup and how much pressure you decide you need. If you regulate your pressure down, you will get more actuations of your air cylinders. Single acting cylinders also use half as much air as double acting cylinders (although they do have some significant drawbacks in many situations).
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Very good point - I should have said reservoir each time. I’ll leave the errors in and add asterisks.
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Our pneumatic kits arrived yesterday. My plan is to strap the cylinder down, place a digital scale in the piston path, and take some pressure readings at differing tank pressures using single action and dual action equipment. And perform this action at differing distances from cylinder to scale… because single action equipment has a spring that works against the piston… lessening its performance the further it strokes.
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If you want to impress judges, compare your actual tests with your mathematical calculation of cylinder force in your engineering notebook. For reference, these air cylinders have a 10mm bore. Also remember to subtract the piston rod diameter from the total area for the double acting cylinder return force.
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