1. Teacher/Mentor Institute Robot Design and Construction Tips Scott McEwen September 15, 2012

2. Overview Engineering Design Process Engineering Design Process Subsystems & System Integration Subsystems & System Integration Communication & Documentation Communication & Documentation Design Engineering & Math Examples Design Engineering & Math Examples Construction Tips Construction Tips Materials Materials Fabrication & Safety Fabrication & Safety Page 2September 15, 2012

3. Engineering Design Process Importance Proven process for any design/build project Proven process for any design/build project Every team is required to submit an engineering notebook that documents the process to design, build, and test your robot Every team is required to submit an engineering notebook that documents the process to design, build, and test your robot Page 3September 15, 2012

4. Engineering Design Process Elements 1. Define the problem 2. Determine the design specifications 3. Develop numerous design alternatives 4. Choose the optimal design 5. Build and test the design Ref: Ref: http://best.eng.auburn.edu/ -> Participants -> Contest Information -> Team Resources -> Engineering Topicshttp://best.eng.auburn.edu/ Page 4September 15, 2012

5. 1) Define the Problem Read the Rules thoroughly at www.bestinc.org Read the Rules thoroughly at www.bestinc.org www.bestinc.org The Competition -> Current Game Rules The Competition -> Current Game Rules Participants -> File Manager -> Public Files Participants -> File Manager -> Public Files Participants -> Contest Information Participants -> Contest Information Password: r1bb0n Password: r1bb0n Inventory Consumable & Returnable Kits Inventory Consumable & Returnable Kits Research similar problems and designs Research similar problems and designs Page 5September 15, 2012

6. 2) Determine the Design Specs Clear guidelines for creating viable designs: Goals Goals Score lots of low point items, then score high point items Score lots of low point items, then score high point items Requirements Requirements Ability to ascend/descend quickly Ability to ascend/descend quickly Ability to grab various game pieces Ability to grab various game pieces Constraints Constraints Must fit in 24 cube and weigh <= 24 lbs Must fit in 24 cube and weigh <= 24 lbs Page 6September 15, 2012

7. 3) Develop Numerous Design Alternatives Engineering design = creative process + content knowledge from variety of disciplines Engineering design = creative process + content knowledge from variety of disciplines Brainstorming Brainstorming Multiple Groups of 3-4? 1+ designs/student? Multiple Groups of 3-4? 1+ designs/student? Sketches, notes, logical & physical models Sketches, notes, logical & physical models Scoring Tip: Brainstorming Approaches: How well organized and productive was the brainstorming approach used and documented? Scoring Tip: Brainstorming Approaches: How well organized and productive was the brainstorming approach used and documented? Page 7September 15, 2012

8. 4) Choose the Optimal Design Weigh and document pros & cons of each design Weigh and document pros & cons of each design Analysis of gaming strategies and design elements to achieve goals Analysis of gaming strategies and design elements to achieve goals Do we have the tools and skills to build it? Do we have the tools and skills to build it? Scoring Tip: Analytical Evaluation of Design Alternatives: Use of analytical and mathematical skills in deciding upon and implementing design alternatives Scoring Tip: Analytical Evaluation of Design Alternatives: Use of analytical and mathematical skills in deciding upon and implementing design alternatives Page 8September 15, 2012

9. 5) Build and Test the Design Invest adequate time and specificity prior to this step Invest adequate time and specificity prior to this step Revisit prior design steps as needed Revisit prior design steps as needed Scoring Tip: Safety Training *and* safety practices followed Scoring Tip: Safety Training *and* safety practices followed Scoring Tip: Support Documentation Scoring Tip: Support Documentation Drawings, photos, test results, etc. Drawings, photos, test results, etc. Page 9September 15, 2012

10. Subsystems & System Integration Drive Platform Drive Platform Ascend & descend Ascend & descend Speed & position control Speed & position control Articulated Arm and end effector (grapple) Articulated Arm and end effector (grapple) Rotate left to right Rotate left to right Extend up & down Extend up & down Extend in & out Extend in & out Grip efficiently Grip efficiently Programming Programming Page 10September 15, 2012

11. Communication & Documentation Communication Best Practices Communication mediums Communication mediums Traditional Traditional Social media Social media SCRUM – Daily stand-up meetings SCRUM – Daily stand-up meetings Other Other Resolving disagreements/conflicts Resolving disagreements/conflicts What works for your team? What works for your team? Page 11September 15, 2012

12. Communication & Documentation Engineering Notebook Document the process used to design, build, and test the robot. Document the process used to design, build, and test the robot. Tell the story of your robot Tell the story of your robot Documentation is a critical aspect of the Engineering Process. Provides: Documentation is a critical aspect of the Engineering Process. Provides: Crucial record of the process Crucial record of the process Critical info between different groups Critical info between different groups Checklist against requirements Checklist against requirements Essential information for new people Essential information for new people Page 12September 15, 2012

13. Communication & Documentation Important Dates Engineering Notebooks are due on Practice Day (Saturday, Oct 20) Engineering Notebooks are due on Practice Day (Saturday, Oct 20) Every team MUST submit an Engineering Notebook Every team MUST submit an Engineering Notebook If no notebook on Practice Day, your team will NOT be able to compete on Game Day If no notebook on Practice Day, your team will NOT be able to compete on Game Day Notebooks will be returned on Game Day Notebooks will be returned on Game Day Page 13 September 15, 2012

14. Design Engineering & Math Examples – Torque Dimensions and torque Dimensions and torque Small Motor Small Motor http://content.vexrobotics.com/docs/276-1610-Drawing-Rev1A.pdf http://content.vexrobotics.com/docs/276-1610-Drawing-Rev1A.pdf http://content.vexrobotics.com/docs/276-1610-Drawing-Rev1A.pdf Large Motor Large Motor http://content.vexrobotics.com/docs/276-1611-Drawing-Rev1A.pdf http://content.vexrobotics.com/docs/276-1611-Drawing-Rev1A.pdf http://content.vexrobotics.com/docs/276-1611-Drawing-Rev1A.pdf Inch-pounds = amount of torque required to lift a 1 pound weight 1 that is 1 inch from axis of rotation Inch-pounds = amount of torque required to lift a 1 pound weight 1 that is 1 inch from axis of rotation Computing torque: Torque = Force * Moment Arm Computing torque: Torque = Force * Moment Arm Torque = Weight (pounds) * moment arm (inches) Torque = Weight (pounds) * moment arm (inches) Total torque = Sum of (weights * moment arms) Total torque = Sum of (weights * moment arms) Page 14September 15, 2012

15. Design Engineering & Math Examples – Torque PVC Pipe @ 0.21 lb/ft PVC Pipe @ 0.21 lb/ft Grapple @ 0.5 lb Grapple @ 0.5 lb Waste Cargo Ball @ 0.4 lb Waste Cargo Ball @ 0.4 lb Page 15September 15, 2012

16. Design Engineering & Math Examples – Torque PVC: (2 ft * 0.21 lb/ft) * 1 ft =0.42 ft-lb PVC: (2 ft * 0.21 lb/ft) * 1 ft =0.42 ft-lb Grapple: 0.5 lb * 2 ft =1.00 ft-lb Grapple: 0.5 lb * 2 ft =1.00 ft-lb Ball: 0.4 lb * 2 ft =0.80 ft-lb Ball: 0.4 lb * 2 ft =0.80 ft-lb Combined: 0.42 + 1.0 + 0.8 =2.22 ft-lbs Combined: 0.42 + 1.0 + 0.8 =2.22 ft-lbs Page 16September 15, 2012 Torque = Weight (pounds) * moment arm (inches)

17. Design Engineering & Math Examples – Torque 2.22 ft-lbs = 26.64 in-lbs 2.22 ft-lbs = 26.64 in-lbs Large Motor torque = 23.53 in-lbs Large Motor torque = 23.53 in-lbs Back to the drawing board Back to the drawing board Page 17September 15, 2012

18. Design Engineering & Math Examples – Motor Specs Page 18September 15, 2012 Futaba S3003 servo Torque: 2.75 in-lb(44 oz-in) Torque: 2.75 in-lb(44 oz-in) Gear Type: Plastic Gear Type: Plastic BEST Small Motor Torque: 9.49 in-lb (152 oz-in) Torque: 9.49 in-lb (152 oz-in) BEST Large Motor Torque: 23.53 in-lb (376.48 oz-in) Torque: 23.53 in-lb (376.48 oz-in)

19. Design Engineering & Math Examples – Potentiometer (Pot) Definition. A Pot is an electrical device whose resistance is adjustable. It can be used as an analog sensor to measure angular position of a rotational component, such as a robot arm. The Cortex can use the Pots output to control or limit some other component. Definition. A Pot is an electrical device whose resistance is adjustable. It can be used as an analog sensor to measure angular position of a rotational component, such as a robot arm. The Cortex can use the Pots output to control or limit some other component. Input. Connect Pots shaft to a rotational axle or shaft. NOTE: the POTs total range of motion (i.e., rotation) is 300 degrees. Input. Connect Pots shaft to a rotational axle or shaft. NOTE: the POTs total range of motion (i.e., rotation) is 300 degrees. Output. Connect the Pots wiring to a Cortex analog input port. Output. Connect the Pots wiring to a Cortex analog input port. Operation. As the resistance of the Pot changes, so does the voltage. This varying voltage can be measured by the Cortex and is directly proportional to the angular position of the Pots shaft. Operation. As the resistance of the Pot changes, so does the voltage. This varying voltage can be measured by the Cortex and is directly proportional to the angular position of the Pots shaft. Data sheet: http://www.bitechnologies.com/pdfs/p160.pdf Data sheet: http://www.bitechnologies.com/pdfs/p160.pdf http://www.bitechnologies.com/pdfs/p160.pdf easyC example: https://sites.google.com/site/team3141rx/easyc/arm3 easyC example: https://sites.google.com/site/team3141rx/easyc/arm3 https://sites.google.com/site/team3141rx/easyc/arm3 Wiring example: Wiring example: http://www.education.rec.ri.cmu.edu/classes/cal_u/ar/toolbox/content/curriculum/robotics_systems/ho me_brew/potentiometer/potentiometer.swf http://www.education.rec.ri.cmu.edu/classes/cal_u/ar/toolbox/content/curriculum/robotics_systems/ho me_brew/potentiometer/potentiometer.swf Page 19September 15, 2012

20. Construction Tips Materials Materials Fabrication & Safety Fabrication & Safety Page 20September 15, 2012

21. Materials Polypropylene Sheet Polypropylene Sheet Aluminum bar, rod, & sheet Aluminum bar, rod, & sheet Steel all-thread rod Steel all-thread rod Wood Wood PVC pipe PVC pipe Electrical Electrical Fasteners Fasteners Miscellaneous Miscellaneous Page 21September 15, 2012

22. Fabrication & Safety Club Workshop Location & Hours Location & Hours 999 Vallejo Street, east of I-25 and north of 8 th Ave 999 Vallejo Street, east of I-25 and north of 8 th Ave 7 days/week, 9a to 11p M-F; 8a to 11p, Sat & Sun 7 days/week, 9a to 11p M-F; 8a to 11p, Sat & Sun Cost: Cost: Special RM BEST rate Special RM BEST rate Call 720-324-7222 for details Call 720-324-7222 for details Tools Tools Woodwork Shop, with CNC router Woodwork Shop, with CNC router Machine Shop Machine Shop Metal Shop Metal Shop Classes Classes www.clubworkshop.com www.clubworkshop.com Page 22September 15, 2012

23. Fabrication & Safety Cutting Plastic Sheet (video) video Wear eye protection & secure work 1. Scribe and break – Sturdy knife Good for 1/8 sheet Good for 1/8 sheet 2. Jig saw – New blade, 10 teeth/inch 3. Band saw – ½-wide blade, 14 teeth/inch May cause melting May cause melting 4. Circular saw – Carbide tip, triple-chip Plywood blade will cause melting Plywood blade will cause melting 5. Table saw – 60-80 teeth, triple-chip, 1/8 to ½ inch blade exposed Page 23September 15, 2012

24. Fabrication & Safety Cutting Aluminum Bar & Rod Wear eye protection & secure work ½-inch Bar ½-inch Bar Hacksaw: laborious and slow Hacksaw: laborious and slow Jig saw: (see notes) Jig saw: (see notes) Band saw: wood-cutting blade Band saw: wood-cutting blade Horizontal band saw: Horizontal band saw: straight & safe straight & safe Visit Club Workshop Visit Club Workshop Page 24September 15, 2012

25. Fabrication & Safety Cutting Aluminum Sheet Tin Snips: laborious Tin Snips: laborious Stop short of full cut to avoid cut marks Stop short of full cut to avoid cut marks Air or power shears Air or power shears Sheet metal shear Sheet metal shear Visit Club Workshop Visit Club Workshop For marking, use ultrafine Sharpie For marking, use ultrafine Sharpie After cutting, dress edges with file After cutting, dress edges with file Page 25September 15, 2012

26. Fabrication & Safety Bending Aluminum Sheet Page 26September 15, 2012 Hand bender Hand bender Vise Vise Sheet metal brake Sheet metal brake Visit Club Workshop Visit Club Workshop

27. Fabrication & Safety PVC and Wood PVC PVC Hacksaw Hacksaw PVC cutter PVC cutter Wood: Holes & round parts Wood: Holes & round parts Drill Drill Drill press Drill press Hole saw Hole saw Page 27September 15, 2012

28. Page 28September 15, 2012

29. Fabrication & Safety Drill Press Speeds (rpm) Page 29September 15, 2012 Bit TypePlywood & Pine AcrylicAluminumSteel Twist, 1/16 to 3/16300025003000 Twist, 1/4 to 3/83000200025001000 Twist, 7/16 to 5/81500 600 Twist, 11/16 to 1750NR1000350 Hole Saw, 1 to 2.5500NR250NR Spade bit w/ spurs, 3/8 to 12000500NR Circle Cutter, 1.5 to 3500250NR Circle Cutter, 3.25 to 6250 NR Circle cutters: Drill 1 st side, flip material over, finish on 2 nd side Wear eye protection & secure work

30. Fabrication & Safety Wear eye protection & secure work Center punch holes to prevent drill from wandering Center punch holes to prevent drill from wandering Clamp work Clamp work Page 30September 15, 2012

31. Fabrication & Safety Fasteners – Drill and Tap Page 31September 15, 2012 Machine Screw Drill Bit Number 1/4-208 #10-3221 #8-3229 Threads are cut inside a hole using a tap Threads are cut inside a hole using a tap Match hole size (numbered drill bit) to screw Match hole size (numbered drill bit) to screw Screws: size – threads/inch Screws: size – threads/inch Purchase drill/tap sets at Ace Hardware Purchase drill/tap sets at Ace Hardware

32. Fabrication & Safety Electrical Components Page 32September 15, 2012 Proper connection of electrical components Mount Cortex for easy access

33. Fabrication & Safety Limit Switches Page 33September 15, 2012 Mini Snap SubMini Snap Connect to digital port Closed = 0 Open = 1

34. Fabrication & Safety VEX Motor Mounting Kit Page 34September 15, 2012 Specifically designed to mount BEST motors Specifically designed to mount BEST motors Flat, but designed to be easily bent Flat, but designed to be easily bent

35. Fabrication & Safety BEST References http://best.eng.auburn.edu/b_game_rules.php http://best.eng.auburn.edu/b_game_rules.php http://best.eng.auburn.edu/b_game_rules.php http://best.eng.auburn.edu/stored_procedures/folder-manager/ http://best.eng.auburn.edu/stored_procedures/folder-manager/ http://best.eng.auburn.edu/stored_procedures/folder-manager/ 1. 2012 BEST Consumable Kit List 2. 2012 BEST Returnable Kit List 3. BEST Large Motor Spec Sheet 4. BEST Small Motor Spec Sheet 5. BEST Generic Kit Usage Guide 6. 3.X VEXnet Firmware Upgrade Utility Operating Instructions and Installation 7. Cortex Microcontroller and VEXnet Joystick User Guide 8. VEX Cortex Pin-out 9. Introduction to easyC & Cortex (Intelitek) 10. Google for PDF: Tools, Tips and Materials by David Kwast Page 35September 15, 2012

36. Club Workshop Location & Hours Location & Hours 999 Vallejo Street, east of I-25 and north of 8 th Ave 999 Vallejo Street, east of I-25 and north of 8 th Ave 7 days/week, 9a to 11p M-F; 8a to 11p, Sat & Sun 7 days/week, 9a to 11p M-F; 8a to 11p, Sat & Sun Cost: Cost: Special RM BEST rate Special RM BEST rate Call 720-324-7222 for details Call 720-324-7222 for details Tools Tools Woodwork Shop, with CNC router Woodwork Shop, with CNC router Machine Shop Machine Shop Metal Shop Metal Shop Classes Classes www.clubworkshop.com www.clubworkshop.com Page 36September 15, 2012