Table of Contents
After a huge success of their Roomba 700 series, iRobot has released a new line of their robotic cleaners. By its looks, Roomba 800 reminds us of classic 700 series, but under the hood is a whole plethora of improvements. Garbage collection bin has been significantly improved, and blade brush and pile brush had been swapped in favor of two lint-less brushes.
Today we’ll take a look at the Roomba 870 and 880 cleaning robots. Let’s see what has changed and whether the new robots are an optimal purchase.
Editor’s Note: The information in this review covers both Roomba 880 and 870 robotic cleaners. For changes specific only to Roomba 870, please refer to “Roomba 870 vs 880” section of this article. Thank you!
As before, the robotic cleaner is made in circular shape.
Bevel from the edge to the bottom of the cleaner helps Roomba 800 better traverse the obstacles, while the small angularity on the top lowers the possibility of the robot being stuck under the obstacles with small gaps.
Roomba 800 has a mainly black matte plastic coating-less chassis. The upper panel perimeter, upper bumper and part of dust collector are embellished with plastic with silver dark gray coating. Circular overlay on the upper panel is made of laminated plastic with barely noticeable concentric texture. Its surface is quite resistant to damage, unlike the central part of upper panel. It is made of dark toned semi-transparent plastic. It covers the LED indicators (touch button labels, charging sign, segmented clock indicator, etc).
On the very center of the upper panel is the circular button with silver coating and concentric grooves imitating chiselled metal. Bezel and labels have green LED indicators; they shine when the robot is online. All buttons are mechanical. To ease the transportation, iRobot engineers have placed a reclining handle on the top.
It has a slight ergonomic oversight – you have to take the handle on the front side, but the groove for fingers is very small. Under the hood is the servicing slot (mainly used for firmware update). Lower part of the bumper is covered with rubber “skirt”, protecting the furniture from scratches.
Upper part is covered with transparent black plastic for IR radiation. Right on the center of upper bumper is the sighting IR sensor. It detects the minimal gap height of fitments. Now let’s get the vacuum upside down and take a look at what’s underneath it.
We have two contact areas, a thruster roller, side brush, battery compartment cap, two steering wheels on spring levers, main brush compartment and the bottom of detachable dust collector.
Six height difference IR sensors are placed by the bottom perimeter, near the edges.
The charging base has the same size as the one used in previous Roomba 500/600/700 series. However, the power supply unit is now attached to the base itself.
This is a very welcome decision. External PSU and extra wires were very uncomfortable. In addition, the base is now more resilient, thanks to the added weight. One more change is the removed external power slot on the robot chassis. It allowed charging the robot without docking it to the base, but it created some extra troubles. The standard power cable is pretty short – only 93 cm long – but you could easily find a replacement cable as the base uses standard “8” slot. A small rubber substrate and a compound platform of foam rubber and unidentified porous material is glued to the bottom of the station.
Thanks to this, the base glues clings well to any surface. Anyway, you can use adhesive tape if you need more. By the way, the base is interchangeable with bases and PSUs from previous models of Roomba.
The vacuum is completed with a IR remote control, two virtual walls and a set of alkaline batteries. In addition, one more filtering element comes straight out of the box.
Now to the documents. We found warranty documents, express manual, a few of supplemental lists and a full user guide written in several languages. The robot itself is packed in a relatively large box with a plastic handle.
The box design is pretty strict but livid, featuring photos, pictures, schemes, kit listing and description of device’s main functions. Ecologically safe corrugated cardboard elements are used as separators. For delivery purposes, the robot is packed in another corrugated cardboard box. This is another welcome solution, as the robot package looks like it’s about to open and everything is about to fall off.
Read the manual to get a better grip at what the robotic cleaner can do. Those who haven’t bought any robotic cleaners before but are interested in purchasing one should download manual from the manufacturer’s website.
Axles of drive wheels are located on the same diameter of chassis circumference. This kinematic scheme allows the robot to turn around itself without changing edges of area, so the robotic vacuum is quite maneuverable. The steering wheels are quite large (71mm in diameter), and the hinge stroke reaches 30mm, so the robot can easily traverse small obstacles. Maximum potential height of obstacle is around 18 mm.
The frontal brush rakes the trash to the center. Its axis is tilted inwards, allowing for better pressure during side-to-front movement phase. The side brush is also well-constructed, with flexible elastic leashes ending with firm straight bristle.
The brush works quite effectively without losing its shape. The self-tapping screw that fixates the brush now also has a wide straight groove, so you no longer need a crosshead screwdriver to install or remove the brush. The model is still compatible with side brushes from previous models.
Two main brushes move towards each other. In 800 Series, they have been replaced with extractors, but just for convenience’s sake, we’ll continue calling them brushes. They are not interchangeable but they have similar construction: external elastic cylinder with ribs (rather silicon-like than rubber) is fixed on firm plastic axis.
The axis is continued with stainless steel pin with yellow plastic sleeve on it. The sleeve is outfitted with bronze sliding bearing. On the other side, the axis ends with a square or hexagon that corresponds to the responding part in brush rotation mechanism.
Foam rubber filler that is located inside the cylinders gives additional elasticity to the external shell. The rotating brushes take the trash from the floor and transfer them to dust collector with airflow.
This construction does not exclude the possibility of heavy particles getting pulled into dust collector, but the probability of such kind of event is now very small, thanks to the new brush construction. Node and detail junctions across the airways now have elastic compactions, while the brush junction is connected to the chassis with sealed elastic air sleeve. It decreases the parasite air suction. The producer also promises higher ventilator power; however, we still have some doubts about real efficiency of such kind of garbage collection system. Let’s see what the tests tell us.
The bottom of the dust collector is made of transparent red toned plastic, but the only transparent part is the narrow stripe. The other surface is covered in matte, so it will be hard to see whether the dust collector is filled just by looking at robot. The dust collector cleaning procedure is quite simple: recline the curtain and shake out the dust. Then disconnect the HEPA filter and clean it as well.
A little note here: this filter uses large-cell grid that does not let large dust reach folded small-pore filter. It makes cleaning the filtering elements easier, improving its durability. Disconnecting the dust collector is quite comfortable, but sometimes you can’t do it with one hand without moving the robot from the base.
Main brush compartment is fixed on levers. With 9 mm stroke, it follows the floor relief, increasing the effectiveness of cleaning. Wired guiding limiters are no more, and we feared that it might cause the vacuum to pull the corners of the carpets on itself.
Dirt Detect 2 is powered by acoustic (purple) and optical (green) sensors. The first sensor detects the dirt level by the noise of dirt particles hitting the microphone. The second sensor consists of IR radiation source and a photodetector. It shines through dust collector on the way to take out trash. Change in IR absorption rate allows the device to track the dust in air and shows whether the dust collector is full.
Everything that requires frequent user care is denoted with yellow. The guide to proper care is printed in the manual, so we are not going to repeat everything. We’ll just underline that the manual has a scheme explaining which elements can be replaced manually – including battery, brush compartment, wheel drives, side brush drive and upper circular panel.
The battery has remained unchanged both internally and externally (maybe except the color) compared to older models. It is fully compatible with Roomba 870, but the manufacturer now promises up to 2x longer service time. This is a very welcome news, as the previous battery lost a big part of its charge after two years of operation. Luckily, there’s no troubles with replacement parts, and with proper care all brushes, filters and mechanic parts will serve you for very long time.
The robot cannot be used in humid areas or to clean surfaces with spilled liquids on them. Vacuum can break down after contact with liquids. No part of the vacuum can be cleaned with water, neither brushes nor filter or dust collector itself. You can only wipe it off with slightly humid mop.
iRobot Roomba 880 has three main cleaning modes:
- Automatically clean all available area and return to base;
- Spot: Intensive cleaning of user-selected area. Robot must be guided with the remote control or carried by user;
- Manual control mode.
You can launch these modes by pressing corresponding keys on the remote or on the chassis. Clean launches standard cleaning, Spot launches local cleaning. Pressing Dock button (three dots on the remote) will force the robot to return to base. You can schedule automatic cleaning for every day of the week with custom time for every day. If you’ve created a schedule, the robot will undock from the base, clean the area and return to base at the time specified. Remote control allows for manual movement and cleaning controls.
There are only five movement commands: move forward, turn left and right, move forward while turning left or right. There is no reverse movement command. The robot will only move when the RC button is pressed. It will automatically engage avoidance maneuver when near an obstacle and turn on docking mode when near a base.
You can limit the area the robot should clean with special devices included in the box (and sold separately if you need more).
These devices work with two LR14 (C, A343 and saline work as well) power elements. They work in two modes: Virtual Wall or Lighthouse. Virtual Wall emits an IR beam that would prevent the robot from traversing any further. This mode is suitable for places that should not be cleaned. Lighthouse sets the cleaning sequence: if the robot gets into the area with a Lighthouse in it, it will not go to other areas until this exact area is spotless. Virtual barrier mode and length are regulated with switches on the device chassis. They will turn on automatically when the robot activates in Clean mode (special RF signal is used) and turn off when it’s complete. This mode is better than activating each virtual wall separately (used in cheaper models) and it significantly improves power draw. As an option, you can buy more “standard” virtual walls and a Virtual Halo – it creates a circular barrier inaccessible for robot.
The robot informs the user about its status with LED indicators. In addition, it plays a short melody when changing states. Should any error happen, it will let the user know by vocalizing the error code. You cannot disable any of these notifications.
The robot spends 15 to 23 minutes to clean the testing area, and then returns to base. More than 90% of the garbage is removed during the first run. Consecutive runs increase the number to 99%.
Only the smallest areas in very hard to reach places and the very edges of the room remained uncleaned. The robot also seems to ignore the space around the base station.
Roomba 880 never moved the base after the cleaning has begun and always docked back with it on first try. We can assume that the robot somehow measures the cleaning area by, for example, average distance from obstacle to obstacle, and identifies how much time is required according to this data. Its calculations are quite optimal, as further increase of cleaning time (more than 20-30 minutes) does not yield significant increase of cleaned trash percentage. The robot is not outfitted with far navigation equipment, but it can decide where to go next, how to get out of complex areas and how to untangle itself from wires. IR proximity sensors, mechanic bumper, wheel and brush turn tracking with optical sensor seem to do the trick.
Judging by how the robot moves during the cleaning, it has several movement options chosen according to its current status, some kind of prehistory and random factor. We found four variants:
- #1 – The robot moves from obstacle to obstacle with subsequent direction change. Used to move in room and to get from one room to another. Possibly used to measure available area;
- #2 – Fan-shaped moves with a return to starting position. Used to clean very dirty areas. The robot actively uses data from ultrasound sensors in the brush compartment and optical sensor in dust collector:
- #3 – Move across the obstacle with right side (where the side brush is located) turned towards it on a small (15-20 mm) distance until IR proximity sensor activates. Used for quick cleaning around walls, small furniture (such as chairs), etc.;
- #4 – Same as 3, but until the mechanical bumper. It lets the robot clean close to any obstacle. Sometimes robot used left side to move across the obstacle.
Regardless of movement option, the robot always cleans. It moves its side and main brushes and turns on the ventilator. If the main or side brush movement is obstructed, the robot activates the release algorithm. It disables the brush drives and continues moving forward. Whatever is stuck on the brushes gets released. Small area (only 5 cm wider than the robot’s chassis) was not a problem, as the robot easily got there during the first cleaning cycle and quickly got out of there.
When the Spot mode is activated, the robot moves in a trajectory of unfolding and then folding spiral. It cleans in an almost circular area with a diameter of 1,2 – 1,3 meters. We have additionally tested a Virtual Wall and a Lighthouse. We placed both devices in the center of testing area, activated one as Virtual Wall and turned on the second as Lighthouse. As a result, the robot has cleaned for 29 minutes in the main part of the room before getting to the “walled” area and cleaning there for 14 minutes. All as planned.
We won’t tell that the additions in Roomba 800 Series seriously increase the quality of cleaning. Roomba 880 is almost indistinguishable from Roomba 780 when it comes to cleaning quality. But the newer models are much more easier to service, as the brushes no longer get any hair, fur and cloth on them. Even if something gets stuck, it can be easily removed. Pet owners will be very happy about it. In addition, new HEPA filter with increased area and a protective grid should prolong its effectiveness both during the cleaning and during the whole term of use. And, of course, improved battery with much longer service time is a blessing.
Roomba 870 vs 880
You could have noticed that, although the article should review both Roomba 870 and 880, we’ve only reviewed the latter. Why, you might ask?
Well, that’s because Roomba 870 and 880 are virtually the same. They both use the same model, same technologies and even share the same appearance. But then, what’s the difference?
The only difference between Roomba 870 and 880 is their package. Roomba 870 comes without a complimentary remote control. In addition, the virtual walls included in the box cannot be switched to Lighthouse mode. That’s basically it. There are no more differences between these two robots. You might save an extra buck by purchasing Roomba 870, especially if you don’t use Spot mode and you have little need in Lighthouse virtual walls. It’s only up to you to decide whether these features are worth extra $50 or so.