1. Warlocks 8/5/05 TMU Pneumatics on Robots u Simplified model Compressed Air Tank Geek Safety Glasses 60 lbs Pneumatic Cylinder Whoa! That’s a lot of force Plunger Diaphragm FORCE= Area of Diaphragm (inches) X Pressure (PSI) in tank. Force = 1.5 X 60 lbf/in 2 = 90 lbs of Force For a 1.5” cylinder bore area r 2 = (1.5/2) 2 = 1.76 in 2

2. Warlocks 8/5/05 TMU Pneumatic Parts u Compressor, 125 PSI, 20 Amps Max, Weight 2.4 lbs –Provides source of pneumatic power u Pressure Switch & gages, 115 PSI high pressure circuit –Pressure switch turns compressor on and off »On at approx. 100 PSI, Off at 115 PSI u Air Tanks – Reservoir so robot functions are not diminished due to loss of pressure - Stores pneumatic power – like a battery –Compressor output will not always keep up with usage »How many on last year’s robot?

3. Warlocks 8/5/05 TMU Pneumatic Parts u Regulator to regulate pressure to components: u Single & Double Solenoid Valves: electrical control from cRio u Flow Control Valves Change speed of extending and retracting: Single=> On=Extend, Off=Retract Double=> Side 1 On Pulse Extend Side 1 Off Same Position Side 2 On Pulse Retract Side 2 Off Same Position Usually it is 60 PSI or Less; 2 Regulators are provided for regulating High Pressure System 115 PSI and Low pressure system 60 PSI simultaneously. Too Fast, Slow it down with Flow control.

4. Warlocks 8/5/05 TMU Pneumatic Parts u Valve to Release or Fill with Air u Fittings u Cylinder (Various Sizes) Diameter Range: ½” to 2” Stroke Range: ½” to 24” Teflon tape helps prevent leaks at connections – don’t use too much

5. Warlocks 8/5/05 TMU Application Information u Force Range @ 100 PSI u Rod diameter – ¼” to ½” –¼” may bend when robots crash into each other u Mounting options

6. Warlocks 8/5/05 TMU Rotary Actuator u Rotary Actuator Rotational Force =Torque (0.075/2) 2 * PI X 60 PSI = 0.26 ft-lbs (0.875/2) 2 * PI X 60 PSI = 36 ft-lbs (1.06/2)2 * PI X 60 PSI= 52 ft-lbs

7. Warlocks 8/5/05 TMU Pneumatic diagram High pressure 115 PSI Low pressure 60 PSI

8. Warlocks 8/5/05 TMU Pros and Cons of Pneumatics u Reasons for using Pneumatics –Weight: May be less total weight than using Gears and Pulleys & multiple electrical motors while keeping the same Force –Simple to Design/Easy to Build: A closed loop pneumatic system is easier to design than gears and pulleys. –Reliable: Pneumatics perform the same over and over again –Force is adjustable and the Force cylinders produce can be significant. –A variety of pneumatic cylinders are offered –We will probably have cylinders already for shifting 2 speed gearbox u Potential Issues with Pneumatics –Pneumatic support system weight – compressor, tanks, regulator, gages »Need all of these components whether we use 1 or 10 cylinders –Stroke Length is limited to 2 ft max. (There are limits). –Fixed increments of travel – full stroke in or out limited variable positions –Need to make sure system is charged before every match –Leaks are possible and can be annoying to find – always plan on putting compressor on robot to avoid complete robot system shut-down

9. Warlocks 8/5/05 TMU Questions?