it is a boundary wire mower, so it does a random walk, bouncing off a high frequency signal that the base station puts around the loop. This means some work to bury the wire around your lawn, but it is €250. GPS RTK models are much much more.
the wire should be inset at least a full mower width from the edge of the lawn, you can always do a quick lap with a manual mower to get the edges every so often. Having it get stuck is more of a PITA, so don't get too close to obstacles.
You can extend the boundary wire, by quite a lot. The limit of 100sqm is nonsense, it will do much bigger lawn areas. You want it to be able to freely bounce around in it's zone though. You can do loops around islands in your lawn for flowerbeds or ponds.
You can get a boundary wire loop sensor for about €20 which helps find breaks in the loops caused by cows getting in to your garden and trampling bloody great holes in your lawn. For example.
The open mower project is based on a Yardforce platform, but not the MB series. The custom motherboard for the GPS RTK open system doesn't fit yet. https://openmower.de/ maybe it will do at some point and you can have an RTK mower that can do stripes.
I believe it comes with 100m length, I think they are a bit confused with length and area, but really it doesn't matter, you can do quite a large area of uncomplicated lawn, but multiple linked areas might end up unevenly mown if you push the limits.
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