Lawnmower robots have much smaller blades with less inertia.
I don’t doubt a direct hit would hurt, but rocks just won’t get thrown very fast by it. A direct hit would also be pretty hard to achieve because the skirt stops anything big from getting under the robot and the blades stop immediately when it gets lifted up.
Just imagine how many lawsuits the manufacturers would have to deal with if these things were only slightly unsafe.
If they are using smaller blades, those blades are most certainly spinning much faster than the large blades of a riding or push mower. Thus you’re just trading mass for speed and the energy exchange can remain largely the same. You can see this for yourself if you drop items (like a handful of sunflower seeds to simulate rocks) through a spinning ceiling fan or a smaller table fan spinning significantly faster; both can easily throw those seeds that get hit by the blades around a large room. This is how the smaller blades on a lawn mower would even be able to do the same work as the larger blades of a mower.
Also many devices, like table saws, chainsaws, and lawn mowers and considered inherently dangerous to operate. Lawsuits over injury as a result of misuse (like letting children or pets into the yard while mowing) usually have to factor in this inherent danger. There are certain safety measures in place, but I guarantee no mower operator manual suggests letting kids or pets play around a mobile set of spinning metal blades. If you fail to follow the basic instructions in an operators manual while operating a dangerous device, you don’t have much ground in a lawsuit.
Lawnmower robots have much smaller blades with less inertia. I don’t doubt a direct hit would hurt, but rocks just won’t get thrown very fast by it. A direct hit would also be pretty hard to achieve because the skirt stops anything big from getting under the robot and the blades stop immediately when it gets lifted up.
Just imagine how many lawsuits the manufacturers would have to deal with if these things were only slightly unsafe.
I’ve read about places banning their use at night because they kill hedgehogs.
Yes, I have heard about that too, which is why I only let mine run at daytime.
That’s not how physics or lawsuits work.
If they are using smaller blades, those blades are most certainly spinning much faster than the large blades of a riding or push mower. Thus you’re just trading mass for speed and the energy exchange can remain largely the same. You can see this for yourself if you drop items (like a handful of sunflower seeds to simulate rocks) through a spinning ceiling fan or a smaller table fan spinning significantly faster; both can easily throw those seeds that get hit by the blades around a large room. This is how the smaller blades on a lawn mower would even be able to do the same work as the larger blades of a mower.
Also many devices, like table saws, chainsaws, and lawn mowers and considered inherently dangerous to operate. Lawsuits over injury as a result of misuse (like letting children or pets into the yard while mowing) usually have to factor in this inherent danger. There are certain safety measures in place, but I guarantee no mower operator manual suggests letting kids or pets play around a mobile set of spinning metal blades. If you fail to follow the basic instructions in an operators manual while operating a dangerous device, you don’t have much ground in a lawsuit.