Inspection-Day Failures: Bumpers, Size, and Weight

Plenty of rookie teams build a working robot and still can't compete because they fail inspection. The fixes are cheap if you know the rules before you build, brutal if you learn them in the queue line. Here are the 2026 REBUILT construction numbers that trip teams up most. Always confirm against the current Game Manual, since rules can be patched mid-season via Team Updates.

Size and weight (2026 Robot Construction Rules). Per R104, a robot's ROBOT PERIMETER may not exceed 110.0 inches and the robot may not be more than 30 inches tall. Per R103 the robot must weigh no more than 115.0 lb without bumpers and battery; per R408 it must not exceed 135.0 lb with bumpers (and battery) installed. (Separately, R105 limits extension beyond the perimeter to 12 inches.) Rookies blow the weight budget by over-building with steel where aluminum or polycarbonate would do, and by adding 'just one more' subsystem late. Track weight from day one; do not weigh once at the end.

Bumpers — the most common inspection failure. Bumpers must protect the robot's corners and:

• extend no more than 4.0 inches from the ROBOT PERIMETER (R403);
• use a minimum 2.25 inches depth of foam padding, at least 4.5 inches tall (R402);
• fill the bumper zone between 2.5 inches and 5.75 inches from the floor (R405);
• fill every corner with uncompressed padding extending at least 2.25 inches from the corner with no gaps (R406);
• keep gaps between adjacent segments under 1.25 inches (R401).

The foam itself is the trap. R402 allows several specific options — pool noodles or backer rod, polyethylene closed-cell foam (1.5–3.0 lb/ft^3 density), EVA closed-cell foam (2.0–6.0 lb/ft^3 density), or foam floor tiles — so the failure is not 'pool noodles' per se but using unapproved foam, the wrong thickness, or padding that doesn't fill the required zone. The other classic mistakes: leaving corners open, and building bumpers that ride too high or too low to actually sit in the bumper zone. Build a wooden bumper jig early and make a red set and a blue set — alliance color is required.

The workflow: print the relevant pages of the official Bumper Guide and the Robot Construction Rules section of the Game Manual, and self-inspect against them with a tape measure before you leave the shop. Bring the foam spec sheet to competition. An hour of measuring at home saves a frantic, robot-down hour in the inspection line.