pic: 1024 Chassis with Biohazard Wheel

[DonRotolo]

Originally Posted by Vikesrock

That rule only limits the intrusion of the ball to 3" inside a mechanism above the bumper zone.

Here is <R19> in its entirety:

<R19> ROBOTS must be designed so that in normal operation BALLS cannot extend more than 3 inches inside
a) the FRAME PERIMETER below the level of the BUMPER ZONE (see Figure 8-5),
b) a MECHANISM or feature designed or used to deflect BALLS in a controlled manner that is above the level of the BUMPER ZONE.

Indeed, Vikesrock's interpretation is what I get as well.