Crab-drive steering modes?

[Dave Scheck]

Originally Posted by gorrilla

hopefully we wont ever have to remove a module after we put it in(we tend to sacrifice weight for strength on our robots,06' escpecially)

Based on experience, expect to replace modules at some point during the season. When we ship the robot, we remove the modules to protect them as well as to help prevent the robot from rolling around in the crate. We also replace them to perform routine maintenance. Most of all, you need to plan for the worst case. If you have module fail, you want to be able to replace it quickly. For us, it's 4 bolts to the mounting plate (you can see it in the bottom left of the picture) and 1 or 2 electrical connections. We've had to use that "feature" a few times in the heat of competition. One year we had our signage fall off and get sucked into the module gearing during a match. Without the quick replacement it would have made it tough to get to the next match reliably.

A big lesson that every engineer should take seriously is that it is critical to design for failure. What happens when it breaks? How will you be able to recover? This applies to all aspects of engineering. On the mechanical side, cars are designed to crash safely. On the software side, divide by zero exceptions are handled to prevent crashes.