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Mechanical Technology Gabriel Orrico Team 303. Importance of robotics Machine Safety Drive train Motor and parts Where to start Preventative maintenance Robot inspection Some ideas. Overview. Teamwork and participation Leadership Science and technology Solve problems.
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Importance of robotics Machine Safety Drive train Motor and parts Where to start Preventative maintenance Robot inspection Some ideas Overview
Teamwork and participation • Leadership • Science and technology • Solve problems Importance of robotics
Its important to keep shop clean Don’t be afraid to ask questions Always wear safety glasses Wear gloves when you can Doesn’t look right = ask General Safety
Secure bit • Make sure fits correctly • Don’t do too much • Wait till bit stops • Advanced: When changing belts, make sure unplugged • Fast = don’t touch Drill Press Safety
Game plan before Firm grip Take time Sharp = don’t touch Band Saw Safety
Correct set-up • Compensate for blade (measure) • Firm grip, stand back • Wait until blade stops Circular Saw Safety
Drive train segment Legend Drive base Wheel Ball caster Pivot point
Four Wheel Drive • Regular drive forward and back • Have to “skid” to turn • Simple • Bad maneuverability
Six Wheel Drive • Regular drive forward and back • Have to “skid” to turn • Relatively simple • Bad maneuverability
Six Wheel Drive contd. Center wheel lowered ¼ inch to provide good turning radius
Two Wheel-Two Caster Drive • Turns like shopping cart. Front “swings around” • Simple • Pretty good maneuverability
Harmonic Drive • Uses Omni-wheel (Above) to turn quickly in different directions with combinations of certain wheels going forward or backward • Four drive motors • Complicated • Good maneuverability
Harmonic Drive contd. Same idea but different configuration
Mecanum Drive • Basic four-wheel set-up with mecanum wheels and four drive motors • Each wheel goes diagonally one way so each needs to be a certain way • depending on spot (4 possibilities) • Similar to harmonic, change directions based on different wheels going different ways • Complicated • Great maneuverability • http://www.youtube.com/watch?v=npWA5AdZIGQ
Crab Drive • Uses wheels but has chain that connects and spins all wheels together • One motor to rotate each wheel, one drive motor per wheel • Very complicated • Great maneuverability • http://www.youtube.com/watch?v=q9uck-wRa_8
Rack and Pinion • Back wheels stationary, front wheels rotate to change direction • Four drive motors • Like a car • Very complicated • Great maneuverability
CIM • Most popular drive motor because it mates to Kit of Parts transmissions from ’05-present • Most powerful motor in the kit – 340W • Fisher Price • Usually come with 100:1 gearbox attached; gearbox has plastic gears • Most often replaced motor in FIRST Components: Suitable KOP Drive Motors
2+ Motors Per Side • Speed and torque are inversely related • Adding motors mitigate the effect of this – a drive train with 2+ motors per side can move a given load faster than a drive train with a single motor per side. • Not worth it! • 2 per side is really all you need Components
Friction Belts • Easily available • Cheap • Will slip under too much load • For some, it’s a feature. For some, it’s a nightmare. Belting
COTS gearboxes are fantastic alternatives for teams without heavy manufacturing capability • They require a bit of extra money, though. • Reliable • Large install-base with troubleshooting experience • A great investment Power Transmissions: Gearboxes
AndyMark Single Speed Gearbox • 12:1 ratio • Mimics previous Kit of Parts gearboxes • Accepts one or two motors • ~$100 ea. Power Transmission: Gearboxes
AndyMark 2-speed Transmissions • Low: 10.67:1; High 4.17:1 ratios • Available with pneumatic or servo powered shifting • Heavier than a custom design • Accepts one or two motors • Several output options • $330+ ea. Power Transmission: Gearboxes
Banebots Planetary Transmissions • Included in 2007 Kit of Parts • 12:1 Ratio • Pretty easy to put on • Versitile • ~$90 • Window motor Power Transmissions: Gearboxes
Conceptually plan, consider priorities • KISS = Keep it simple, stupid • RRRR = Reliability, Reparability, Relevance and Reasonability • Build test field, parts • Create CAD/paper design early • Order parts (Mcmaster-carr), prepare key members • Modular? • Build robot • Allow extra time for building, practice • Plan B bot? Where to start
A check over all systems before every match • Prevents major repairs from being needed • Allows for optimal performance • Make a check list • Check once the robot gets back • Again when robot is going to next match • Two person job Preventative Maintenance
Bolts should be checked for tightness • Chains taught • Battery charged • Check key features first • Gearboxes • All motor attachments • Problem spot that the team knows of Preventative maintenance checklist ex.
Mandatory • Do it early so the problems can be fixed • No sharp edges • Team number and school name visible • Electrical wires safe • Keep record of purchases, parts • Go to inspection with bumpers off, wear gloves and have bill of materials • Design award: Team member to talk to judges Robot Inspection
2013: Frisbee launcher • http://www.youtube.com/watch?v=8KVK8svZzbI • http://www.youtube.com/watch?v=tLHyVlUO5jo Ideas – how to play this year’s game
Importance of robotics Machine Safety Drive train Motor and parts Where to start Preventative maintenance Robot inspection Some ideas Summary