[Marc P.]

At the NYC Regional this year, 2836's robot was fully assembled for the first time Thursday morning. First thing we did was throw it on the inspection scale- 124.1 pounds. We had anticipated being ~5 pounds overweight, and had the materials on hand to replace a number of steel pillow blocks and idler shafts with aluminum spares. All told, we ended up at 119.8 pounds in time for our first qualification match.

Over the course of the day, we tweaked a few things, adding and subtracting little parts here and there. To be prepared for the impending elimination match re-inspection Sunday, we weighed in again Saturday night (this being a Fri-Sat-Sun regional), and again were at 119.8.

So Sunday rolls around, and we make it to the elimination rounds. Being as far behind schedule as they were, event officials called for elimination robots to be quickly re-inspected- meaning a quick once over, and weight to be checked with batteries and bumpers installed.

The idea was, take the total weight of the robot, subtract the recorded weight for the bumpers (from the original inspection), and subtract a standard weight for the battery (something like 13.3 pounds). With bumper and "battery" weight subtracted, our robot was calculated to be 121.4 pounds.

Not understanding how we suddenly gained 1.6 pounds, I instructed our students to quickly remove the bumpers. Subtracting the "battery" weight still landed us at 121.4 pounds. I unplugged and removed the battery, and the scale fluctuated between 119.9 and 120.0 pounds.

Lesson learned- battery weight isn't always standard, especially if you have a decent length of 6 gauge wire with the Anderson connector attached.