What is Reddit's opinion of Wood Circles 24 inch, 1/8 Inch Thick, Birch Plywood Discs, Pack of 1 Unfinished Wood Circles for Crafts, Wood Rounds by Woodpeckers?
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a lot of robot vacuums have problems with bases like that (bar stools, etc).

one way of dealing with it is to raise the chair just enough that the bumper sensor hits it and retreats instead of trying to climb it.

you could attach something like this to the bottom:

mock it up first with magazines or something to figure out how high it has to be to make the robot reverse when it hits it

< $50

< $25

< $25