Spring loaded Pneumatic piston

[BJT]

the spring in these cylinders is usually very light. I was looking at a 1.5 inch bore single acting spring return cylinder and the specs said the spring had only about 6 pounds of force. I think the spring is always used to return a single acting cylinder, not to assist its push.

[Team2191]

Originally Posted by BJT

the spring in these cylinders is usually very light. I was looking at a 1.5 inch bore single acting spring return cylinder and the specs said the spring had only about 6 pounds of force. I think the spring is always used to return a single acting cylinder, not to assist its push.

if we were to use a spring loaded cylinder we would use the 2" bore with a 4" stroke and a front spring bias. this accomplishes the extra force needed and the extra velocity. the spring described in this system has 30 lbs. force by itself. with the pneumatics added this will be increased more. btw this is offered by clippard

[DonRotolo]

Originally Posted by Al Skierkiewicz

If these types of cylinders are used, some part of the robot can move when the valve is opened.

No different than if I tied some latex surgical tubing to the end of the cylinder rod, which would retract it if air pressure was released.

However, your point about safety is an excellent one: A gentle movement to a safe position with air release is one thing, but I can imagine some violent stuff that can happen when air is released (or lost) which could be quite dangerous and must be avoided.

[joeweber]

We are using a 2x4 piston (cylinder) with added springs to move a hamer type kicker. It would not kick fast until we removed the cylinder. We found that the exhause valve was not allowing the air to escape fast enough. Would a different valve work ar maybe a larger hose and valve? We were thinking of doubling up on the ehaust valve and hose to allow more air flow.

[DonRotolo]

Originally Posted by joeweber

maybe a larger hose and valve?

It may be helpful to peruse the rules.

<R72> In addition to the items included in the KOP, pneumatic system items specifically permitted on 2010 FRC ROBOTS include the following items. All included items must be “off the shelf” pneumatic devices rated by their manufacturers for pressure of at least 125psi, and used in
their original, unaltered condition (except as required for assembly with other components).
<snip>
C. Solenoid valves. All such valves must have a maximum ⅛” NPT port diameter, and a maximum Cv of 0.32 (if non-KOP valves are used, the team will be required to provide part documentation validating that the valves meet these constraints).
<snip>
E. Additional 0.160” inch inside diameter pneumatic tubing functionally equivalent to that provided in the KOP, with the pressure rating clearly factory-printed on the exterior of the tubing (note: alternate tubing colors are acceptable).