How the iRobot Looj Works

The iRobot Looj aims to clean out gutters remotely, so people can avoid the dangers of the task.
The iRobot Looj aims to clean out gutters remotely, so people can avoid the dangers of the task.

Every homeowner knows that cleaning gutters is a pain, but did you know that it can be hazardous to your health? According to the U.S. Consumer Product Safety Commission, hospital emergency rooms treat more than 164,000 ladder-related injuries each year -- and 17,124 of those were head injuries in 2007. [Source: Department of Health and Human Services.] It's hard to clean gutters without getting on a ladder, so it's no surprise that inventors are constantly trying to come up with better, safer ways to do the job.

In September of 2006, iRobot (creators of the Roomba, a robotic vacuum) sponsored an internal design competition to generate new product ideas. Jim Lynch, an electrical engineer with the company, decided to tackle the "dumb, dirty, and dangerous" job of gutter cleaning [Source: BNet]. He began tinkering with an electric screwdriver and toy truck, and the resulting design won the competition. One year later, iRobot released the Looj, a remote-controlled robot that's designed to motor through gutters and pitch out any debris in its path.

At 2 1/4 inches high and 31/4 inches wide (5.72 by 8.26 centimeters), the Looj is slim enough to travel through a standard gutter. Two treads run the entire length of the Looj, which helps it tackle uneven ground. At the front of the Looj is a replaceable three-stage auger -- that's the part that's actually supposed to shovel the leaves out of your gutter. Topping it all off is a removable handle that doubles as a remote control, allowing the operator to stay in one place while driving the Looj up and down the gutter. With the remote you can change the direction of the auger so that you don't end up with leaves all over your roof. You can also reverse the Looj if it runs into an impassable clog, or if you simply need to bring it back to you.

Now that you know the story, let's find out what makes the Looj tick.


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?

Using the Looj

Let's take a step-by-step look at using the Looj. Once it's out of the box and charged, put on the belt clip and slide the Looj onto the hook so that you can climb the ladder hands-free. When you've reached the gutter, use the handle to place the Looj inside, positioning it so that the auger faces the section of gutter you want to clean. Release the handle from the robot and use the controls to direct the auger properly and drive the Looj down the gutter. If it gets stuck, or if you're ready to move on to another section of the gutter, you can put the Looj in reverse and bring it back to you. When you've finished all of the gutters, snap the handle back into place, lift the Looj out of the track and hang it back on the belt clip for the climb back to the ground. Use a garden hose to spray away any gunk the Looj accumulates while doing its job.

One of the most helpful aspects of the Looj is the belt clip, which is included with every type. It allows you to keep your hands on the ladder as you climb it. Since the goal of the Looj is to minimize the risk of cleaning your gutters, this is a key add-on.

The removable handle and remote control is another plus. Overreaching while working on a ladder can make you lose your balance, so staying in one place and maintaining your footing is important. The remote control allows you to direct the Looj from afar without sacrificing safety.

One common problem with the Looj, however, is that the robot apparently doesn't perform well with non-standard gutters. For example, if there are inconsistencies in the gutter's surface, the Looj might have a hard time going over the uneven terrain. If you have an older home with smaller gutters or lower gutter straps, the Looj can easily become stuck. If your home has an uneven roofline, you'll need to make numerous trips up and down the ladder to reposition the Looj, as it does not travel around corners. In other words, the Looj probably isn't for everybody. But, if your house has a simple roofline with newer industry-standard gutters, it might work well for you.

Looj Alternatives

The Looj, shown above, is one way to avoid climbing ladders, but there are others products available that perform similar tasks.
The Looj, shown above, is one way to avoid climbing ladders, but there are others products available that perform similar tasks.

Of course, the Looj isn't the only product available for those who want to avoid ladders as much as possible. Depending on what you've got in your garage, there could be something on the market that will work with the tools you already have. If you have a wet-dry vacuum cleaner, you can purchase certain cleaning accessory kits to add to it. A wet-dry vacuum has the capability to either blow debris out of the gutter or vacuum it up, depending on the situation. That set-up allows you a little more flexibility when tackling either a major clog or a light infestation of leaves. And, with an extender that hooks over the edge of the gutter, the operator can remain on the ground for most of the cleaning.

The same principle applies to two other types of products: gas-powered blower attachments and hose attachments. Likewise, you can find gutter-cleaning attachments for power washers and even garden hoses.

Of course, any of these extension tools require that you do the work almost entirely blind. If you run into a particularly vicious clog or just want to make sure you've left no leaf unturned, you will still need to use a ladder to get a closer look. But, like the Looj, all of these tools reduce the number of trips you make up and down the rungs.

As autumn approaches, those of you with gutters will be contemplating ways to keep them clean and leaf-free. Make sure you know what kind of gutters you have; it's likely you'll be able to find a product on the market that can help you. And, if you end up on a ladder, remember to be careful.

For lots more information on the Looj and related topics, see the links on the next page.

Related HowStuffWorks Articles


  • Clark, Emily. "iRobot Looj cleans up at innovation awards." GizMag. Nov. 13, 2007. (Sept. 2, 2009)
  • Consumer Product Safety Commission. "Ladder Safety Alert." 2009. (Sept. 9, 2009)
  • Flight, Georgia. "How They Did It: Seven Entrepreneur Success Stories." Bnet. April 18, 2008. (Sept. 2, 2009)
  • U.S. Department of Health and Human Services. "Ladders, Swings, and More Can Cause Peril." April 2009. (Sept. 8, 2009)
  • Vishots. "iRobot Looj -- Inventor discusses gutter cleaning robot." YouTube. April 30, 2008. (Sept. 2, 2009)