Examples of when it is not advantageous to be lightweight

[jwfoss]

Originally Posted by Andrew Lawrence

Part is maneuverability, though the main reason is I just can't think of a reason to be heavy. 1323's resources make machining for weight easy enough, and I think it would be a useful engineering goal for the kids to shoot for in season to design for a lightweight yet strong robot if the game allows for a lightweight robot as a viable strategy. Also it would be a good way to allocate weight lower into the drivetrain to make a lower CG (which has been a clear problem for us this year).

One of the first things many mentors I have learned from tend to tell me is how to lighten a robot and that "lighter is better" (not always true, but it's a point that has been stressed enough to me in my education that I started this thread because of it, though further learning could prove differently) and while I understand the potential advantages of a lower weight, I cannot think of many reasons for increased weight. More mass in a robot just makes it harder to move, and I don't see any advantages to that, and want to learn what I may be missing.

If you have the resources to design strong and light, then that's fantastic. You have the opportunity to test out how adding weight to different locations on your chassis change the handling dynamics of your robot. I would argue that the location of your weight (most notably your CG) is far more important to drivetrain handling then the actual weight of the machine. Thinking a little bit more into this, there are incredible number of factors that play into "handling". Wheel selection, wheel spacing, chassis rigidity, and even the driver controls.

Being "heavy" is not just about increasing the ceiling of your pushing ability but also your resistance to being pushed, or slowed down. Momentum is a very real thing in FRC games. On FRC558 we design to be "light", and then add weight low to balance our chassis. Also we make sure that our bumpers are just under the limit (its "free" weight in the right place, low to the ground). Again, we believe in having a strong chassis and drivetrain because we believe that defense is just as important as offence in most years.