1. Drivetrains Beach Cities Robotics – Team 294 Andrew Keisic June 2008

2. 2 - Introduction / Agenda Sources Copioli and Patton’s “Robot Drive Systems Fundamentals” presentation

3. Topics 3 - Introduction / Agenda Center of Gravity Types of Drive Trains Maximizing Design Motor Performance Gear Ratio Calculation

4. Center of Gravity A point in space where gravity acts Why it’s important? Determines the balance and stability of an object

5. Center of Gravity Stability - what ball is the most stable? the least?

6. Center of Gravity What robot is the most stable? The least? How do you know? What systems are inherently stable?

7. Center of Gravity Putting math behind intuition Stability Triangle h b2b2 b1b1 α1α1 α2α2

8. Center of Gravity Limit of stability is determined by the CG location In other words – the maximum ramp angle of a stationary robot β1β1 β2β2 α1α1 α2α2

9. Center of Gravity Why keep it low? Lowering the center of gravity maximizes alpha! Stability Triangle h b2b2 b1b1 α1α1 α2α2

10. Center of Gravity BCR 2008 FRC initial CG estimate

11. Type of Bases

12. Drive train configurations simple rear wheel drive simple front wheel drive simple all wheel drive simple center drive 6 wheel drive tracked drive There is no “right” answer! swerve/ crab drive other?

13. Types of Bases simple rear wheel drive

14. Type of Bases simple front wheel drive

15. Types of Bases simple all wheel drive

16. Type of Bases simple center drive

17. Types of Bases 6 wheel drive

18. Types of Bases tracked drive

19. swerve/ crab drive

20. other?

21. Maximizing Design Designing is all about tradeoffs Speed vs torque Low CG vs reaching high Weight vs features Control vs power

22. Maximizing Design Requirements Before designing a system, we must know what it needs to do The design requirements usually stem from the game Strategy plays a big part in the requirements Decide the requirements as a team For competitive robots, torque is always needed We’re going to design for maximum torque – pushing ability

23. Maximizing Design: Motor Performance