1. FTC Mechanical design considerations 2012 edition by: Andrew Rudolph

2. What we’re going to talk about the rulesmanipulatorsideas

3. 2012-2013 rules You’ve already read them right?

4. rules Only can use preformed robotics components from: Lego Tetrix Matrix

5. matrix Observed at World Cmp Designed to bring costs down of FTC overseas Designed off standard lego grid Different motors Different motor controllers Different Gears and wheels Possibly thinner metal Belt system CV Axles Check some of the offerings at: http://matrixrobotics.com

6. matrix http://www.chiefdelphi.com/forum s/showthread.php?t=106017

7. rules Only COTS (Custom Off The Shelf) items allowed: Linear Slide Non-motorized Turntables and Lazy Susan Lead screws and threaded rod plus compatible nuts Servo Blocks #25 Chain and connector or half links

8. rules Unlimited in quantity or size of the following: Raw material available to all teams from standard distributors Standard bearings or bushings Fasteners Rope, Cord, Cable, monofilament, … Rubber bands Latex tubing Zip ties Nonslip pad without adhesive backing Electrical solder, tape and any type of glue/cement Any COTS lubricant as long as it doesn’t get on stuff

9. materials Extrusions Readily available from many retailers Cut and drill with simple tools Strong and lightweight Most commonly 6061 Aluminum 7075 Aluminum for higher strength www.onlinemetals.com www.8020.net

10. materials Sheet metal Readily available from many retailers Cut and drill with simple tools Or Water Jet, Laser Cut, CNC Break for complex parts

11. materials Plastics Lexan (NOT ACRYLIC) easy to find and work with Bend with heat Lots of shapes and different mechanical characteristics available Polycarbonate (lexan) Coroplast Sintra Teflon Nylon Delrin HDPE

12. materials Plastics You can now Rapid Prototype Parts! You can now 3D print Parts! ABS Polycarbonate PLA

13. materials Rope, cord, etc… Steel wire rope Solid steel wire Paracord Braided fishing line 150 lb test = 0.56mm diameter

14. Shoulder Bolts materials drive components Bushing 6338K3116338K311 @ McMaster for $0.75 ea! Drill rod (tool steel rod) 88725K3388725K33 @ McMaster for $2.68 for 3’ Lead screw or Acme screw Linear Bearing Lubricants

15. Lifts! You mastered these last year…right?

16. lifts We saw them last year

17. lifts What did we miss last year? Precision liftingVariable position liftingLifts go upLifts go down

18. lifts Scissor lift Short height, Wide base Lift over base Requires lots of power Lots of moving parts Difficult to synchronize two sides Difficult to lift from ground Difficult too have finite control Poor lateral loading

19. lifts FRC 343 circa 2000 Lead screw or Acme screw

20. lifts Single joint arm Simple to build Can move fast Can reach fore and aft Light weight Object orientation changes Strong Lateral load Lift outside base Object orientation changes Difficult to multi position Do not lift high

21. lifts multi joint arm Lots of freedom keep lift inside or outside of base complex to build heavy Lots of motors Difficult to control

22. lifts Four bar linkage Simple to build Light weight Object orientation stays the same Lift outside base Lots of torque required at shoulder

23. lifts six bar linkage twice the weight of four bar Object stays the same Higher lift than four bar Lift outside base Lots of torque required at shoulder More joints to create friction and wobbles

24. lifts Telescoping Straight lift multiple positions small footprint COMPLEX difficult to maintain high CG

25. lifts hybrid Combine multiple mechanisms

26. Ideas General design practices

27. ideas Are you going to… acquire it? manipulate it? store it? lift it? position it? release it? What tasks within my strategy do I need to perform? Let strategy drive your robot design, not the opposite

28. ideas What does the game piece look like from the robots POV? What are all the ways the game piece could lay? What is the most usable or stable position? How does the object react? Think like a robot about the game piece

29. ideas Maximize your “Acquisition Zone” other design considerations

30. ideas other design considerations Alignment Devices

31. ideas other design considerations Make it easy to drive

32. ideas other design considerations Will stray objects interfere?

33. ideas other design considerations Keep your Center of Gravity (CG) low

34. ideas other design considerations Design is an iterative process

35. Just the parts you want to work. ideas Really, simple IS better. Some design mantras You don’t have to prototype everything… Assume nothing. Sometimes wild ideas lead to champions.

37. Celebrity Endorsed.