Louvre Pyramid glass cleaning robot. 0:35 video:
https://www.youtube.com/watch?v=9PVbZY7owsQ
More: https://en.wikipedia.org/wiki/Louvre_Pyramid
Previously:
https://www.homemadetools.net/forum/...001#post125290
https://www.homemadetools.net/forum/...960#post133808
https://www.homemadetools.net/forum/...369#post131305
https://www.homemadetools.net/forum/...295#post121722
https://www.homemadetools.net/forum/...059#post103138
