First came push mowers. Then power mowers. Now there are robotic mowers that let you put your feet up. Consumer Reports tested two. They don’t come cheap. Friendly Robotics RL1000 RoboMower costs $2,000. LawnBott’s LB3200 Evolution goes for $2,500.

Testers found a safety problem with the LawnBott that could injure an adult or curious child. When you lift it up, the blade keeps spinning. You could reach in and get a nasty injury. If you lift it up further, the blade will stop, but it takes several seconds.

A spokesperson for the U.S. distributor of the LawnBott told Consumer Reports that there’s a software update for the LawnBott 3200 Evolution so the blade stops within a second after it’s lifted above 35 degrees. But Consumer Reports says even with that change, the robotic mower poses a serious risk. Consumer Reports has reported the problem to the Consumer Product Safety Commission.

The RoboMower does not have that safety problem. Lift it up just a little and the blades stop quickly. The RoboMower is designed to work several hours every day or two, trimming off a little bit of grass as it moves about in a random pattern.

To keep it in your yard, the RoboMower is supposed to turn around when it reaches a wire you lay around the perimeter. And it’s supposed to go to a home base for a recharge once its battery runs down.

But you can’t just start the RoboMower and forget it. Consumer Reports found that there were times when the RoboMower just stopped dead and it actually had to be picked up and physically returned to its charging station. There were other times that the RoboMower went outside its perimeter wire and the testers had to chase it down.

Consumer Reports says all in all a regular mower does a better job and is a whole lot cheaper.