CCEFP HANDS-ON
PNEUMATICS WORKSHOP
Instructors Guide
ver 0.4
Pneumatics Workshop
1
Overview for Instructors
The CCEFP hands-on pneumatics workshop demonstrates basic fluid power and
basic pneumatics in a hands-on activity. The activity was created by the CCEFP
with additional funding support from Donaldson, a CCEFP industry member,
through The Donaldson Foundation. The workshop can be conducted in as little
as 45 minutes, or can be expanded to one-half a day or more. The workshop is
designed for a range of student audiences including undergraduate engineering,
high school and middle school. The primary target audiences are high school
FIRST Robotics teams and students in Project Lead The Way pre-engineering
courses. All components in the kit are industrial grade and are what can be
found in a typical industrial pneumatics application. Additional information
about the pneumatics workshop is at
www.me.umn.edu/~wkdurfee/projects/ccefp/pneumo-kits/
For questions or comments about the workshop, please contact Professor Will
Durfee, University of Minnesota, wkdurfee@umn.edu, 612-625-0099
The Center for Compact and Efficient Fluid Power (CCEFP) is a network of researchers,
educators, students and industry working together to transform the fluid power industry.
The CCEFP mission is to create hydraulic and pneumatic technology that is compact,
efficient and effective. The CCEFP education and outreach program is designed to transfer
this knowledge to diverse audiences including students of all ages. The CCEFP is a National
Science Foundation Engineering Research Center, established in June 2006. In addition to its
grant from NSF, the CCEFP is supported by its seven participating universities and over 50
industrial partners. Complete information about the CCEFP is at www.ccefp.org.
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For 5-kit traveling set
Ref Quant Description
In the large hockey bag
K001
5
bicycle pump
K002
5
cylinder (mounted to paint can, with cap)
K003
7
plastic catching cup (2 spares)
K004
5
support stand with post
K005
5
yardstick
K006
1
Discovering Fluid Power DVD
K007
1
Instructors spare parts bag (see below)
5
Kit bags (see below)
Parts list
In each of the five 2.6-gal zip lock kit bags
K008
1
fill valve
K009
1
power supply (tank, relief, fittings)
K010
1
pressure gauge
K011
2
pneumatic switch
K012
1
cylinder (with wing nut and washers)
K013
2
fitting, tee
K014
2
fitting, plug
K015
1
air tubing, 5/32", 12 ft, cut into pieces
K016
1
right angle clamp
K017
1
tennis ball
K007
5
5
5
5
2
1
10 ft
2
2
3
1
1
1
n
INSTRUCTOR SPARE PARTS BAG, in 1 g zip
10-32 fender washer
10-32 lock nut
10-32 nut
10-32 wing nut
3/8 washer
tennis ball
tubing, one piece
tee fitting
plug fitting
cap
pressure gauge
Other (from CCEFP web site)
Instructor's Guide
presentation slides
student handout
K008
K010
K002
K011
K003
K012
K004
K013
K014
K009
K016
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Push to Connect Tubing Fittings
To disconnect, push this collet against
body then tug on the tube until it
releases
To connect, push tube
into fitting until it
seats
Use orange plug fitting to block open ports
More tubing can be cut from the spare roll. Use scissors.
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Ball Catch Activity
Hint: Do not show this picture to the
students because it is a better learning
experience for them to figure it out on
their own.
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The Basics
•
The standard kit packaging is a set of five kits in a large, wheeled bag.
•
•
In advance, lay kits out on the table
Start by presenting a brief lecture on fluid power. CCEFP lecture notes are
available
If time, then show first part of CCEFP/NFPA/TPT video, “Discovering Fluid
Power”
Split into teams of three and start them building
Hints
•
•
•
– See the inventory of kit contents. Each station gets the parts that are in the 1 g
zip-lock bag plus one of each part in the hockey bag.
– If parts get lost, see the BOM spreadsheet on the project web site for where to
order replacements
– Let teams discover how to put things together; only provide hints if absolutely
needed; discovery is part of the learning process.
– In advance, show them how the push to connect fittings work
– It is almost impossible for anything to break, so no need to hover over the teams
– Do make sure that when connected the bicycle pump is pumping directly into the
air tank. The air tank relief valve is set at 60 psi, which means the entire circuit
is safe.
– Advise students to keep their faces away from the cylinder rod when
manipulating the air switch as the rod can extend forcefully.
– Structure in a 4-minute clean up time to insure that everything gets back into
the 1 g zip lock and that stations do not cross-contaminate parts. There are
many small parts!
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Suggested Flow
• "Can you find a way to generate compressed air?"
– They will find the bike pump
• "You'll need something to store the compressed air. Anything in
the kit?"
– They will find the tank/relief valve assembly
• "Connect the bike pump to the tank and pump air through it"
– It will take them a long time to discover the pump fitting, but resist
the urge to help. Encourage them to use longest length of tubing
between pump and tank so that the pump stays on the floor and the
tank on the table. The open end of the tank can be closed with an
orange plug. Teams will jump when the pressure relief valve spits; its
fun. Keep an eye out for teams connecting the pump to anything other
than directly the tank because otherwise you can pump without the
relief valve in the circuit, which is bad.
• “You need a way of measuring the pressure in the system. Can
you find a part that will help? Good, connect it to the circuit
– It will take them a while to figure out that it takes a tee fitting to
connect up the pressure gauge, but eventually they will get it. Have
them pump and read the pressure. Encourage use of short tubing for
this, but on the other hand, they can just learn on their own. The
more you stay out of their way the better, even if you don’t “like” the
way they are completing the task. This is hands-off instruction!
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Continuing on
• Hold up a cylinder. "This can extend when compressed air flows
into this port, and can retract because of a spring when the air is
released." Hold up a toggle-lever valve. "Here is a hand-operated
valve. Your challenge is to construct a circuit where the piston
goes in and out when you flip the toggle on the valve back and
forth."
– It may take them a while to discover how to hook things up. Resist the
urge to give them the answer. Eventually they will get it.
– When the circuit is working, ask them to notice hat happens to the
pressure with successive flips of the switch
• Hold up the big coffee can with the cap on top. "There's another
cylinder in here. Perhaps with this setup and a tennis ball you
could make something interesting."
– Eventually they will make a ball launcher
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The challenge
• Show them the small plastic tub, the lab stand, and the black
right-angle lab clamp. "Are you ready for the really big challenge?
A ball launcher is fine, but it would be even cooler if you could
catch the ball. Perhaps you could attach that first cylinder to the
lab stand with a clamp (don’t screw down too hard on the cylinder
as it may kink), and perhaps you could attach this plastic tub to
the cylinder rod (sandwich between the two large washers on the
rod), then hook up the cylinder to the second switch. If you then
adjust things just right and get the switch timing just right, you
might be able to launch and then catch the ball."
– It may take them a while to figure out the right way to fasten the
cylinder to the support and the can to the rod, but eventually one
team will get it and the other teams will copy. Encourage anchoring
can and stand in place with your hands.
• You can stop the activity here or go on
– If this is the end, have teams disassemble and place everything back
in their bag. Be sure the hardware (two washers, two wing nuts) stays
on the cylinder rod. The two tees and two plugs go into the small ziplock. The big items go into the large duffle bag. Consult kit list for
what goes where.
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Stage 1 Circuit
(A later version of the instructors guide will have proper schematic symbols in the drawings)
RELIEF
VALVE
PUMP
TANK
Plug the end with an orange plug
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Stage 2 Circuit
RELIEF
VALVE
P
GAUGE
PUMP
TANK
Plug the end
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Full Circuit
CYLINDER
CYLINDER
RELIEF
VALVE
P
GAUGE
PUMP
TANK
VALVE
VALVE
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Extra Stuff
•
Activity: Using the yardstick, create a plot of ball launch height versus tank pressure
•
Activity: Determine lift capacity versus pressure
–
When labeling axes, point out the importance of including units, e.g. "height (in.)“
–
–
Need way to measure weight of books or other objects
Balance weight on launch cap and pump until it just lifts. Record the pressure. Or, pump to known pressure,
extend the launch cylinder, then gradually add objects of known value to the cap until the cylinder just retracts.
Advanced students can predict the force by knowing the pressure and the piston area. Piston is 7/16” bore
(diameter).
–
•
Activity: Launch height versus tube length
•
Activity: Launch height versus load weight
•
Activity (advanced): Efficiency
–
–
For same pressure, first measure launch height with short tubes connecting tank to switch and switch to tank.
Repeat for very long tubes.
This experiment demonstrates there is air drag in the tube.
–
Launch things other than tennis ball and measure height
–
Calculate stored energy in tank (tank volume is 8.7 cu. in.). Calculate potential energy change for ball at peak
height. From these two numbers, calculate the efficiency of the launch system.
•
Activity: Pressure loss per operation
•
For FIRST Robotics teams, make the connections between the workshop and the pneumatics
components in their FIRST kit. Brainstorm on how pneumatics can be used in the competition
robot.
Discuss computer controlled valves. (Note that computer controlled kit parts are under
development by CCEFP)
•
–
Pump up tank, then record pressure versus operation cycle for successive operation of the cylinder with the
switch. Where does the pressure go? (Volume of system increases when cylinder extends dropping the pressure.
When cylinder retracts, that extra volume of air is exhausted to atmosphere through the switch.
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Nothing is sacred. Be inventive and report your
results and ideas to Will Durfee, wkdurfee@umn.edu
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