ROOMBA-BOT behaves exactly like a Roomba, except it doesn’t clean or do anything useful. All ROOMBA-BOT knows how to do is drive around the room and avoid obstacles in its path. ROOMBA-BOT uses a laser rangefinder to detect when objects are near. The program continually reads the output of the rangefinder, backing up and turning when the distance measurement becomes low. The casing of ROOMBA-BOT is made from an ultralight cellulose matrix and fastened together with zero-tolerance joinery. We used a semi-gloss black finish and gray decals to imitate the Roomba’s original design. ROOMBA-BOT is built to an approximate 4/5ths scale compared to the original Roomba. We moved the rangefinder from its original position in the kit by stripping the ends of male-to-female wires and using them to attach the module lower down for better sensor results. This way, objects closer to the ground were detected and avoided. One challenge we faced was how motor performance differed between cable and battery power. We built our program by testing performance with the cable, and then saw vastly different performance with the battery power. Because the motors operate by time and not by degrees of rotation, a change in power caused completely different robot behavior.