I know blades are suppose to be good for a year or more, but after a month or two mine becomes out of balance due to grass buildup and duller from an occasional stone or branch/trigs we might miss. So I have developed my own technique in sharpening and balancing my Lawnbott blades, taking only a minimum amount off blade every 2 months or so.
It's been working for me. If interested you can view my steps on YouTube titled "Sharpening a Lawnbott Blade"
https://www.youtube.com/watch?v=o0KXLZ6jNi0&feature=youtube_gdataIf you decide to sharpen/balance your blades, do it at your own risk as Lawnbott doesn't recommend it do to safety reasons!
