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Comment by jeremysalwen | Hacker News Reader

I run an Open mower on my 1400 square meter lawn in the USA. AMA. (ps. If you are interested make sure to go to the discord instead of just reading the docs or GitHub pages -- that is where all the activity is!)

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The page says there's no obstacle avoidance. How does it handle obstacles? Does it at least have a sensor to detect it running into an obstacle to then find some way around it? This would be the main concern for me.

Also, how long have you had it and about how much downtime have you had?

It does not have obstacle avoidance, the best it has is recognizing it keeps getting stuck and skipping the next goal until it finds a goal it can reach. This can often look like obstacle avoidance since the next goal might be in a slightly different direction and so it will be able to continue. This is aided by a new feature that I added which will make the mower back up first when it gets stuck before continuing.

However, I should note that it's a hackable ROS system, so people have added obstacle detection with various sensors on their mowers. There is just not official support or a standard way to do it.

I've mowed with it this summer and last summer, and there hasn't been downtime at much as repeatedly getting stuck and requiring me to bring it back to the dock (although less and less). But my lawn is probably the hardest lawn any Openmower mows, as I mentioned in a cousin comment.

How difficult was it to get the needed hardware in the US? It seems hard or expensive to do so.

The yardforce500 is hard to find in the USA, but it's extremely cheap in Europe. I found a great deal and paid $208 for the mower and $135 for a package forwarder to ship it from Germany. I have a complete spreadsheet of my expenses here: https://docs.google.com/spreadsheets/d/1BV8VCtqTer8iodXvyRd1...

Nice!

How much time did it take you from the moment you started the project to the point where it fell like it was up & running?

It's hard to put a specific number on it, since it's been progressively improving the whole time I had it. I bought it in the fall of 2023, and got it "running" then, but it was not actually doing any useful work. Summer of 2024 it was doing useful work but required constant hand holding and a series of hardware and software upgrades to get it more stable. This year it is actually doing the majority of the mowing. It still requires frequent rescue but it's a lot less work than actually mowing the lawn myself.

However my lawn is probably the most difficult lawn of any openmower user. I'm in Vermont, so I have very steep terrain, a bumpy yard, poor GPS reception, very wet weather, and also my lawn is very large and complex shaped. For a simple use case it would be working great a long time ago. I also chose to do a "Mowgli" build which is based on more reverse engineering, which added complexity and unreliability (but saved some money).

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