Struggling with stored energy

[Grog_Maelstrom]

If I have a cylinder(we never have used pneumatics on our team) and it pulls back 10 inches storing over 100 lbs of force, how fast can we release the arm to not slow down the 100lbs with resistance.

IE if it pulls back surgical tubing 10 inches and then extends, how fast can I get it going?

Im concerned that I have been unable to locate rules on speed of air released through solenoids.

-Grogo

[jee7s]

The energy storage has to be in compliance with the rules. Since the situation you describe deals with air and deformation of robot parts, you're in compliance with the rules.

The rate that the cylinder can move is dependent on the resistance to flow into the cylinder. The biggest resistance to the flow is the solenoid valve. The rating for the solenoid valve's resistance to flow is the flow coefficient (Cv). Cv is generally defined as the flow rate of water through the valve in gallons per minute when the pressure across the valve is 1 PSI. Yes, it's defined with water, but the principle applies to air as well. If you use a solenoid valve with a Cv that is large, the air flows faster and the cylinder hence moves faster.

In past years there has been a limitation on Cv. This year's rules do not have a Cv limit. See R77 for the rules regarding solenoid valves. Then, pick a valve that is within the rules and allows your cylinder to move fast enough for your application.

Keep in mind that inspectors will look closely at robot safety. If they feel your mechanism is not sufficiently safe, they won't let you compete with it.

[dellagd]

Could you describe your mechanism more? Are you using cylinders and pistons in tandem in your system?

[IKE]

Please do add some more details as my first understanding of how your system is set up could result in the air cylinders disassembling themselves...IE, the piston in the cylinder could hammer against the end very hard if the surgical tubing is helping accelerate it as well as the air pressure.

[Grog_Maelstrom]

Thanks for the help. The idea is that a cylinder pulls pack on a compression spring that then we release, impelling the ball with force under the equation


(force released in the spring) - (resistance from cylinder)

where (resistance in cylinder) is limited by the pressure