iRobot Looj Mechanics
So, we know what the Looj does: It pitches all the dead leaves out of your gutters. But how does it do that? Pretty much all of the heavy lifting is accomplished by the auger. Augers are essentially long screws, and they work by agitating whatever needs to be moved -- a clump of leaves, in this case -- in order to break it apart. The Looj's auger has flexible flaps that scoop up the debris as the auger turns and propel it away from the gutter. And, because gutter maintenance is a heavy-duty job, the Looj has treads instead of wheels. iRobot also produces machines for the military, and inventor Jim Lynch borrowed the same design for his project. Treads offer the Looj a higher rate of friction than wheels, which means that the Looj is less likely to get stuck on the job. It's not afraid of getting wet, either -- the Looj is capable of working in up to one foot (0.305 meters) of water.
The auger is powered by an internal motor, which is in turn powered by a replaceable and rechargeable battery. The Looj is designed to run on 7.2 volt nickel-cadmium batteries, which are used in other products such as exit signs, model airplanes and power drills. Both the auger motor and the drive motor get their directions from an electronic controller with a memory store that contains the necessary instructions. This electronic controller is housed within the Looj's removable handle, which itself is powered by two AAA batteries.
Once removed from the main robot, the handle serves as a remote control. Good at a distance of up to 75 feet (about 23 meters), the control transmits directions via radio frequency to an antenna built into the main housing of the robot. In earlier models, the antenna was external; although it was flexible, it often got caught on gutter straps.
But does the Looj really work as advertised? And what other gutter-cleaning gadgets are out there?