I tried a robot vacuum with a mechanical arm

Robot vacuums are developing new features very quickly. A year ago, self-scrubbing docks that emptied dirty water into an on-board tank to keep mop pads clean and dry were a fresh innovation. Then, the robots developed wheels and legs that let them hop over tricky room transitions.

Now Roborock is first to market with the next big trick; a robot with a full mechanical arm folded into its body, designed to physically pick up and relocate objects in its way.

Roborock’s fine print says the Z70 can spot and sort socks, sandals, tissues, and towels. But it turns out there are a few more limitations.

The idea seems like pure science fiction. Imagine that, while you’re out of the house, a robot emerges to vacuum and mop. It gets in all the nooks and crannies and, if you’ve left any small objects on the floor, it picks them up. You’ll find them neatly placed where they’re supposed to go — or stowed in the robot’s own little lost-and-found basket — when you get home.

It’s an intriguing glimpse of the future, but Roborock’s $4000 Saros Z70 can’t make it a reality quite yet. The company says the robot can only pick up a very few objects, including socks, cloths, tissues and sandals. And, as I found out, it will only do that in very specific scenarios.

The bot comes with a sleek and futuristic-looking dock, plus a gaudy cardboard bin covered with QR codes into which it can deposit objects. After setting it up and letting it map my house (which it did quickly thanks to its cameras and sensors), I immediately enacted a simple test I thought would be a slam dunk for the robot arm. I decluttered the kids’ bedroom and placed a single sock in the middle of the floor, then asked the robot to come and vacuum.

It began cleaning in a grid and clearly saw the sock, as it deviated from its pattern to carefully clean around it. Then it finished the job and returned to its dock. Strike one, the sock was still on the floor.

Upon checking the app, it seems the robot detected the sock as a generic obstacle. My fault, the sock wasn’t socky enough. I chose an unmistakable specimen for the second test; white and well-worn, with a green toe. The very visual definition of a sock. The robot avoided it completely. Strike two.

I decided to change tack and replace the sock with a kitchen cloth. The robot ran over it, dragging it around the room. Strike three.

At this point the floor was very clean and I just wanted to see the grabber, so I activated the manual mode that let me take direct control. The arm looks as you’d expect; a five-axis black robotic pincher on a pole, with neat cabling. It’s impressive that it fits in the robot, but I hate to think what could happen if debris gets stuck in its hidey hole before it returns home.

I pointed out where the sock was and asked the robot to collect it. It said there were no liftable items in view. I switched the arm to manual and controlled it to grab the sock in a surprisingly tight grip, then drove the robot to its bin to deposit it. A fun novelty, but more work for me than just picking up the sock.

It took some figuring out to get the robot to pick things up automatically. As it turns out, any socks, cloths or tissues need to be rolled up in a ball for the robot to grab them. Any slippers need to have their opening facing the middle of the room for the arm to scoop them up. It won’t grab anything near a wall, or anything weighing more than 300 grams, and it won’t attempt to grab anything on carpet.

With all that in mind, my revised test was to place a single sock, rolled into a ball, in the middle of the tiled hallway. The robot spotted it, picked it up with a somewhat unsettling mechanical squeal, and deposited it in the basket before returning to clean. A good demonstration, if a highly artificial one. It also passed tests with other objects placed on tiles – all either slippers or rolled into balls. You can set it to put different objects in different places; slippers in front of the bed for example, socks in the bin, and it does so.

But that’s all in very deliberate testing. Not once has the robot picked something up and sorted it while carrying out its regular cleaning duties. It’s just supremely unlikely that an object in its way would tick the required boxes to activate the arm. That’s not to say the feature is hopeless; Roborock says it will improve the grip in software updates, enabling it to pick up more objects in more situations. But right now, you’d be taking a gamble on that being useful.

Assuming you were interested in paying a premium for a robotic arm vacuum, you’d likely be very happy with the rest of the Z70’s features as well.

The robot’s a relatively compact unit that can squeeze under gaps of eight centimetres, its mop and side brush come out on little extenders to get into corners, it’s good at vacuuming up hair without getting its rollers tangled, and it integrates well with smart homes. The dock can remove and store the robot’s mop pads when not needed, clean them automatically in 80°C hot water and dry them. It has a lifting chassis that can carry wet mop pads over short carpet, or hop over thresholds of around four centimetres. And it generally does a very good job of vacuuming and mopping.

The only problem is, you can get all of that in a robot that costs less than $3000, including the Dreame X50 Ultra and Roborock’s own Saros 10R. An extra $1000 for a mechanical arm, which is currently not much more than a novelty, is a steep ask.

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