While both low and high end robotic vacuum cleaners have much in common when it comes to overall design philosophy, Karcher dares to be different with their RC 3000 RoboCleaner. What makes it different? The robot's base station automatically empties the dirt from the robot so you don't have to. Many folks have expressed a great desire for this feature, and the Karcher is currently the only robotic vacuum to offer it. Since you don't have to empty the robot's dirt bin every two hours, the vacuum can clean literally all day long without human intervention. To top it off, you won't have to invert and bang a dust bin over your trash can, sending dirt back into the air and your lungs. This and the RC 3000's ability to reliably return to its base station for cleaning and charging then set out again cleaning make it a very autonomous and worry-free robotic vacuum.

The Karcher's sizeable base station has a powerful vacuum cleaner built in, and when the robot docks for charging and cleaning, the base station automatically vacuums the robot, sucking the dirt out via the dirt inlet opening underneath the robot. The base station's vacuum sounds like your average non-robotic vacuum cleaner, running at 60 dB on a 600 watt motor. It takes approximately two minutes to empty the robot's .2 liter dirt receptacle. The base station uses vacuum cleaner bags with a 2 liter capacity.

Design

The RC 3000 looks similar to other robotic vacs like the Roomba Discovery. The roving pizza shaped cleaner weights only 4.4 pounds and measures 11" in diameter and 4.1" high. It's a tad smaller than the compact Roomba Discovery and is the smallest consumer robotic vacuum on the market. It has a unique design that prevents it from getting stuck under furniture: two "ears" on each side have a gentle ramp-up design that allows the RC 3000 to go under furniture without squeezing in where clearances might be too tight to prevent it from exiting.

The batteries are located under the unit and are easy to reach should you need to replace them. The bottom plastic plate and brush are also easy to remove, making cleaning a breeze.

Controls, Operation and Base Station

The RC 3000's controls are located on the base station rather than on the robot. Controls are minimal since the robot is designed to be a set and forget unit. The controls consist entirely of buttons and LED indicators, and there is no LCD. You'll use the buttons to set the cleaning duration: 3 hours for a 150 sq. foot room, 6 hours for up to a 300 sq. foot area, 9 hours for up to 450 sq. feet, and "permanent" cleaning which means the robot runs continuously. Those may sound like long cleaning times, but the Karcher needs long runtimes since it doesn't have the most powerful vacuum motor and it returns to its base station frequently for charging and self-cleaning, which means it really isn't spending all those hours cleaning.

Above: the robot in the base station

The base station measures 19"deep x 10" wide x 9" tall and should be placed against a wall for stability. A snap-on ramp attaches to the front and the robot drives onto the ramp for docking. When docked, an inlet in the ramp area sucks dirt out of the robot through the robot's vacuum inlet. The robot also charges when docked via contacts on the side. To remove the base station's vacuum cleaner bag, simply open the door on the top and remove the bag. Removing and fitting bags is easy and similar to standard vacuum cleaner designs. Both the robot and base station have power buttons.

The robot returned to its base station 100% of the time, and then went on its merry way cleaning when charged. It is very reliable and well designed. When it resumes cleaning it does seem to return to the area near where it had been working rather than starting from scratch.

Above: pop open the lid on top of the base station to remove the bag

Battery and Runtimes

Since the RC 3000 is designed to run unattended for hours, returning to its base station as needed for charging and cleaning, concerns about runtimes aren't as meaningful. It will run for the designated cleaning time and charge itself during that time period so you need not worry about runtimes (as long as the robot and base station are on the same floor of the house). The robot can run up to an hour on a charge, but when started from its base station, or if it's encountered it during the cleaning run, it will return for charging well before the battery has depleted. Karcher says that it will run at least 20 minutes before returning to the station and it did indeed run about that long before making a maintenance pit stop. The unit keeps a lot of power in reserve to ensure that it has enough juice to find its way back to the base station. Autonomy is an important part of the RC 3000 design, and Karcher insures that you won't come home to a robot that ran out of power before it found the base station.  In fact, the RC 3000 did an excellent job finding its base station even in a multi-room setting.  Like all robotic cleaners, it can't go up and down stairs, so you will need to have the base station on the same floor as the robot so it can make charging and emptying pit stops.

Sensors

The Karcher has cliff sensors that detect drops and prevent it from falling down stairs or over ledges and landings, making this vac completely stair-safe. How does it deal with obstacles? Like many other robotic vacuums, the RC 3000 has bump sensors that tell it when it's contacted an object. The robot bumps gently into obstacles and turns away to continue cleaning. The bumper is very soft and unlike Roomba, is non-moving so it's very quiet when making contact with objects. The Karcher will not damage furniture or mar surfaces with its bumper and is painless and safe when it makes contact with your foot. Since it uses only bump sensors to navigate obstacles, you will want to pick up pet water dishes or very light items that might otherwise be moved or sucked up by the vac.

Cleaning Ability and Methods

The one area where the Karcher falls short is in cleaning power. It has relatively weak pick up power and is out-sucked by Roomba and other robo-vacs with the exception of the Zoombot which is even weaker. Since the RC 3000 doesn't have a strong motor it is uncannily quiet. Karcher states that you can run the vacuum overnight which at first seems absurd, but once you hear how quiet this unit is, you'll realize you might indeed allow it to clean while you're sleeping. To that end, the base station has a button that allows you to put it in quiet clean mode. Why? Because the base station's vacuum motor which cleans the robot is quite loud and would likely wake sleepers. In quiet mode it is indeed quiet, though it can take several hours rather than a few minutes to empty the robot when in quiet mode.

In hard floor tests on a 150 sq. foot mix of linoleum and Pergo, the RC 3000 picked up about 85% of visible debris when left running for a 3 hour period. Though it passes over each area several times, the vacuum motor isn't powerful enough to suck up all the dirt that it encounters. The robot does have dirt sensors so it's aware of areas with high dirt concentrations and slows down to spend extra time cleaning those areas. The vacuum inlet isn't very large at 3.75" x 1.5" so the robot shouldn't manage to suck in large items, but that means it also doesn't get a lot of coverage per pass.  Inside the inlet you'll find one brush bar with a row of standard vacuum bristles. On low to mid-pile carpeting, the Karcher got most visible surface dirt but wasn't able to remove dirt below the surface. It didn't raise the nap of the rug to give it that "just vacuumed" look. The vac handles pet hair and dirt equally well.

The robot uses what Karcher describes as a random pattern, but like all robotic vacs, it does have some behavioral patterns

Does it Get Stuck?

Robotic vacuums do get stuck occasionally, either wedging under furniture or sucking in rug fringe. But the Karcher never got stuck! The cleverly designed ears on top stop it from wedging itself under tight places and it really didn't have enough suction to pull rug fringe or area rugs into the inlet which would cause it to get stuck. Add another point for autonomy and unattended operation: this unit should rarely get stuck when you're out of the house.

Conclusion

This is certainly the most care-free robotic vacuum we've tested. It doesn't get stuck, reliably returns to its base station for charging and cleaning and resumes cleaning, and you need not empty the robot's dirt receptacle. If it had more cleaning power, it would be on the top of our list, but alas it just doesn't suck enough, and vacuums must suck. It's best used on hard surfaces since the vac motor isn't strong enough to pull much dirt out of carpeting.

Estimated US Price: $1,500

www.karcher.com

http://www.robocleaner.de/