26-07-2014, 12:10 PM
Pneumatics
[attachment=66261]
Introduction
Weight
– Much lighter than motors (as long as several used)
● Simple
– Much easier to mount than motors
– Much simpler and more durable than rack and
pinion
● More rugged
– Cylinders can be stalled indefinitely without damage
– Resistant to impacts
● Disadvantage: All the way in or all the way out
Introduction
Components
Mechanisms
ResourcesFIRST Robotics Competition
Regulator
● Allows air
from reservoirs
to flow to rest
of pneumatic
system
● Limits pressure
in valves,
cylinders to
60 psi
Double Solenoid Valve
● One solenoid pulsed to move cylinder one
way, other solenoid pulsed to move cylinder
the other way
● Results unpredictable if both pulsed
● Valve will stay in either state when neither
solenoid energized
● Can use one relay for each solenoid or one
relay and two diodes
Cylinder Tips
● If you need the piston to stay extended or
retracted, add a mechanical latch
● Be careful to ensure the
piston rod cannot get bent
● Hard to get locknuts/lock
washers in large sizes, so
nuts on pistons likely to
come loose
Fittings
● Put Teflon tape on all threads to ensure
a good seal
– Do not put tape on first two threads, as it
may come loose and clog up a valve
● Tubing attached simply by pushing it
into connector
– If you have a leak, try cutting off the last
couple centimeters of tubing; if it is
damaged, it will not seal properly
– To detect leaks, put soapy water on
suspect connections and watch for
bubbling
Introduction
Components
Mechanisms
ResourcesFIRS
[attachment=66261]
Introduction
Weight
– Much lighter than motors (as long as several used)
● Simple
– Much easier to mount than motors
– Much simpler and more durable than rack and
pinion
● More rugged
– Cylinders can be stalled indefinitely without damage
– Resistant to impacts
● Disadvantage: All the way in or all the way out
Introduction
Components
Mechanisms
ResourcesFIRST Robotics Competition
Regulator
● Allows air
from reservoirs
to flow to rest
of pneumatic
system
● Limits pressure
in valves,
cylinders to
60 psi
Double Solenoid Valve
● One solenoid pulsed to move cylinder one
way, other solenoid pulsed to move cylinder
the other way
● Results unpredictable if both pulsed
● Valve will stay in either state when neither
solenoid energized
● Can use one relay for each solenoid or one
relay and two diodes
Cylinder Tips
● If you need the piston to stay extended or
retracted, add a mechanical latch
● Be careful to ensure the
piston rod cannot get bent
● Hard to get locknuts/lock
washers in large sizes, so
nuts on pistons likely to
come loose
Fittings
● Put Teflon tape on all threads to ensure
a good seal
– Do not put tape on first two threads, as it
may come loose and clog up a valve
● Tubing attached simply by pushing it
into connector
– If you have a leak, try cutting off the last
couple centimeters of tubing; if it is
damaged, it will not seal properly
– To detect leaks, put soapy water on
suspect connections and watch for
bubbling
Introduction
Components
Mechanisms
ResourcesFIRS