ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 1 Introduction to Machining & Electronics and Pneumatics Lecture #5a

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 2 Introduction to the ME2110 Kit Controller Box Electro Mechanical Actuators & Sensors Pneumatics

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 3 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 4 Layout of I/O Ports Motor_1 Motor_2 Battery Charger On / Off Switch P1P8P6 P5 P4 P3 RS-232 Connector P7 - Start P9 - Speaker RF / RS-232 Selector P11 P12 P14 P13 P15 ResetID Inputs Outputs

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 5 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 Battery Charger On / Off Swit ch P1P8P6 P5 P4 P3 RS-232 Connector P7 - Start P9 - Speaker RF / RS-232 Selector P11P12 P14 P13P15 ResetID

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 6 Electro/Mechanical Supplies

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 7 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 8 Solenoids Consists of a coil of wire – Electromagnet When powered up, pulls in plunger.

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 9 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 10 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 11 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 12 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 13 Best Way to Learn is to Do Read through the manual Examine the sample programs and program fragments Studio assignment Ask questions Additional Information – (BASIC Stamp)

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 14 Pneumatic Supplies

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 15 Pneumatic Actuator Pressurized Extension Spring Return 2.5 in Stroke

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 16 Pressure Vessel Pressurize with Bike Pump Max 100 psi Supplies Actuator strokes

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 17 Pneumatic Valve

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 18 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 19 The Coupler  1/ /2-20 UNF 6-32 UNC THRU  DP All tolerances  unless otherwise specified

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor The Lathe

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 21 Process Plan for Coupler (1) 1) Chuck OD, face one side, turn 75% of shaft to diameter 2) Turn X diameter segment 3) Drill X diameter hole using tail stock 4) Flip part in lathe and chuck on diameter.

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 22 Process Plan for Coupler (2) 5) Turn X diameter segment 6) Thread 1/2-20 UNF segment using 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 thread use the head from the drill press or mill to keep the tap straight.

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 23 Important Notes Do not remove more than inch per cut Cross slide readings are radius, not diameter –Removing inches from the part will result in the diameter being reduced in size by inches –Do not to hit the chuck with the cutting tool when machining.

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 24 The Bracket

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 25 The Mill

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 26 Process Plan for Bracket (1) 1) Mill outside dimensions 2.30 X X 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 27 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 X inch grove sawing from the top to the first 3/4 inch hole rotating the part 90  sawing to the next 3/4 inch hole rotating the part 90  sawing back to the top

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 28 Process Plan for Bracket (3) 5) Mill the slot that was roughed in operation 4 1/4 diameter mills will yields a 1/8 inch radius 6) Drill (using the #25 drill) and tap the threads use the head from the drill press or mill to keep the tap straight.

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 29 Bracket Important Notes Do not remove more than 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 30 Don’t Rush Ask Questions

ME 2110: Creative Decisions and Design Prof J.Rhett Mayor 31 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