Quote:
Originally Posted by Abhishek R
On our 2013 robot, which did not auto shift, we often had trouble starting in 2nd gear, and it seemed to take a toll on the batteries whenever we tried. The robot simply did not like to get going very quickly in 2nd gear, so we started in 1st and upshifted to 2nd once we had some motion.
Do you have any guesses as to why this may be?
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Well, I took a glance at your season highlight video, and the first thing that struck me was your wheels. How much did they weigh? They look relatively heavy. If you were rolling on heavier wheels (especially if a lot of that weight is concentrated ~4" from the center in the thick rubber tread), the wheels' moments of inertia can come into play. It probably took a lot more torque to get those wheels rolling than lighter ones like the VexPRO traction wheels (6" in 2013, 4" in 2014) that we've used.
One of the first things that comes to mind when you wonder about the physics of accelerating a robot is inertia, but rotational inertia can become a big factor too in some designs. That's my best guess as to what it was, especially if you didn't have as much of a problem with it in other years.