FIRST Robotics 101

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FIRST Robotics 101

• Week 1) Gears, Pulleys, Sprockets, Bearings
• Week 2) Motors Controls
• Week 3) Pneumatics
• Week 4) Materials Fasteners
• Week 5) Drivetrain and Framing Options
• Week 6) Arm Winch Options
• Week 7) Team Building

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Have You Got Gas? Do You Have a lot of Hot Air?

• Then you will probably like Pneumatics!
• Pneumatics- Compressed Gas
• The most famous Pneumatic invention of the 20th
  century was the Pneumatic Tire.

Imagine a tire without air (solid tire). What a
rough ride! In the 1920s and 1930s came a new
smooth riding tire Its Pneumatic (full of
pressurize air) and made for a smoother ride..
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And in the 21st Century they put Pneumatic Tires
on Robots

• Robots now have a smoother ride with Pneumatic
  tires, but that is not exactly what FIRST meant
  when they said Pneumatics. This is what they
  meant

Whoa!
Pneumatic Cylinder
Safety Glasses
Compressed Air Tank
Geek
Plunger
Diaphram
FORCE 60 lbs to 100 lbs
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ForcePressure X Square Area

• Calculations

Stroke Length
Pneumatic Cylinder
Compressed Air Tank
Plunger
Diaphram 1.5 Sq Inches
FORCE Area of Diaphram (inches) X Pressure (PSI)
in tank.
60 PSI
1.5 X 60 90lbs of Force
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Pros and Cons of Pneumatics

• Reasons for using Pneumatics
• Weight May be less weight than using Gears and
  Pulleys while keeping the same Force with perhaps
  the exception of the compressor.
• Simple to Design/Easy to Build A closed loop
  pneumatic system is easier to design than gears
  and pulleys.
• Force is adjustable and the Force pneumatic
  produces can be significant.
• Offers movement or actuation in a straight line
  rather than rotational movement.
• A variety of pneumatic cylinders are offered.
• Issues with Pneumatics
• Compressor weight (7 to 10 lbs) need to keep air
  usage to a minimum to not use compressor.
• Stroke Length is limited to 6 inches to 2 ft max.
  (There are limits).
• Need to fill tanks after every match besides
  changing battery.
• Leaks are possible and can be annoying to find.

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Pneumatic Parts

• Compressor, 125 PSI, 20 Amps Max, Weight 7.5 lbs
• Pressure Switch, 115 PSI
• Air Tanks (2 per robot) small (Remember Not Much
  Air)

Can be put on Robot but I have not seen any of
robots have the weight in six years!
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Pneumatic Parts

• Regulator to regulate pressure to components
• Single and Double Solenoid Valves
• Flow Control Valves Change speed of extending and
  retracting

Usually it is 60 PSI or Less 2 Regulators are
provided for regulating High Pressure System and
Low pressure system simultaneously.
Singlegt OnExtend, OffRetract Doublegt Side 1
On Pulse Extend Side 1 Off Same
Position Side 2 On Pulse
Retract Side 2 Off Same Position
Too Fast, Slow it down with Flow control.
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Pneumatic Parts

• Valve to Release or Fill with Air
• Fittings
• Cylinder (Various Sizes)

Diameter Range ¾ 1 ½ 2
Stroke Range ½ to 24 Force Range at
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Forces of Cylinders

• Force Range

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Rotary Actuator

• 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
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Pneumatics