Post on 27-Dec-2015
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Introduction to Machining&
Electronics and Pneumatics
Lecture #5a
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Introduction to the ME2110 Kit• Controller Box• Electro Mechanical Actuators & Sensors• Pneumatics
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Features of the Controller Box
• BASIC Stamp II-SX microcontroller• Interfaces with various external devices
– Stepper Motors– DC Motors– Pneumatic Valves– IR Distance Sensor– Flex Sensor– Microswitches– Solenoids
• RS-232 Communication Port
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Layout of I/O Ports
Motor_1
Motor_2
BatteryCharger
On / OffSwitch
P1P8P6 P5 P4 P3
RS-232Connector
P7 - Start
P9 - Speaker
RF / RS-232Selector
P11 P12 P14 P13 P15
ResetID
Inputs
Outputs
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Interfacing the BASIC Stamp• Connections
– P1: Flex Sensor– P3-P6: Microswitches– P7: Microswitch that will
be used to start competition
– P8: Distance Sensor– P9: Speaker– P11-P15: Solenoids, DC
Motors,Pneumatic Valve
– Large Plugs: Stepper Motors
Motor_1
Motor_2
BatteryChargerOn / OffSwitch
P1P8P6 P5 P4 P3
RS-232Connector
P7 - Start
P9 - Speaker
RF / RS-232Selector
P11P12 P14 P13P15
ResetID
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Electro/Mechanical Supplies
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Microswitches
• Lever arm closes circuit
• Status of IN register holds status of port– 0 = Open Circuit– 1 = Closed Circuit
• Same action is going to start competition
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Solenoids
• Consists of a coil of wire – Electromagnet• When powered up, pulls in plunger.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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DC Motors
• Speed is proportional to voltage
• Moves in one direction
• Gearbox to slow down shaft
• Very high torque• Requires time to
ramp up and down.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Stepper Motors
• Both motors are controlled through P10
• Speed is a value chosen between 2 and 240
• Can move both directions
• Negligible ramping time
• Low Power
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Flex Sensor
• Detects deflection• Works like a strain gage
– Resistance changes with deflection– Voltage reading sent through A/D converter– 12-bit output (0 – 4095)
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Infrared Distance Sensor
• 4” to 30” Range• Infrared beam is emitted• Beam reflects off object• Detected by receiver• Output voltage
proportional to distance• A/D Converter: Reading
between 0 and 255.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Best Way to Learn is to Do
• Read through the manual • Examine the sample programs and
program fragments• Studio assignment• Ask questions• Additional Information
– www.parallaxinc.com (BASIC Stamp)
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Pneumatic Supplies
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Pneumatic Actuator
• Pressurized Extension• Spring Return• 2.5 in Stroke
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Pressure Vessel
• Pressurize with Bike Pump• Max 100 psi• Supplies 10-15 Actuator strokes
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Pneumatic Valve
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Machining Studio
• Learn to Respect Machine Tools• Learn to Cut• Gain Experience• Generate Design Ideas• Build Confidence• Preserve Digits
Goals:
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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The Coupler
0.500 0.650 1/32 0.750
1/2-20 UNF6-32 UNCTHRU
0.125 0.750 DP
0.900 0.500
0.250
All tolerances 0.010 unless otherwise specified
0.500+0.000-0.005
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
The Lathe
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Process Plan for Coupler (1)
1) Chuck OD, face one side, turn 75% of shaft to 0.900 diameter
2) Turn 0.750 X 0.500 diameter segment
3) Drill 0.750 X 0.125 diameter hole using tail stock
4) Flip part in lathe and chuck on 0.900 diameter.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Process Plan for Coupler (2)
5) Turn 0.500 X 0.500 diameter segment
6) Thread 1/2-20 UNF segmentusing lathe tail stock to keep
the die straight
7) Mount the part in either a mill or drill press
8) Drill (using #35 drill) and tap 6-32 UNC threaduse the head from the drill
press or mill to keep the tap straight.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Important Notes
• Do not remove more than 0.020 inch per cut
• Cross slide readings are radius, not diameter– Removing 0.010 inches from
the part will result in the diameter being reduced in size by 0.020 inches
– Do not to hit the chuck with the cutting tool when machining.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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The Bracket
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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The Mill
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Process Plan for Bracket (1)
1) Mill outside dimensions 2.30 X 0.950 X 0.950 part
2) Mark part off for operations 3 and 4 using a felt tip pen. Make sure to leave material for milling the final part.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Process Plan for Bracket (2)
3) Drill 3/4 inch holes near 1/8 inch radius corners
Drill holes in material to be removed
You will use these holes for turning points during sawing.
4) Rough saw 0.700 X 1.500 inch grove
sawing from the top to the first 3/4 inch hole
rotating the part 90sawing to the next 3/4 inch hole
rotating the part 90sawing back to the top
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Process Plan for Bracket (3)
5) Mill the slot that was roughed in operation 41/4 diameter mills will yields
a 1/8 inch radius
6) Drill (using the #25 drill) and tap the 10-24 threadsuse the head from the drill
press or mill to keep the tap straight.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Bracket Important Notes
• Do not remove more than 0.020 inch per cut
• Do not to cut into the machine itself when end milling– elevate the part to provide some clearance
between the machine and the cutting tool.
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Don’t Rush
Ask Questions
ME 2110: Creative Decisions and Design Prof J.Rhett Mayor
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Franciscan friar William of Ockham
OCKHAM’S RAZOR –
entia non sunt multiplicanda praeter necessitatem
Translation:
entities should not be multiplied beyond necessity
OR:
All things being equal, the simplest solution tends to be the best one
Good guidance for DFM efforts
Simplest design/process is usually the most producible