Good to know.
I'm sourcing some materials right now. It might not be ideal, but I'm trying to design something around a 180mm, several 160mm, 100mm and 80mm wide steel u-profiles I got for free and a base plate 33x33cm that is 25mm thick with 25mm thick braces that is welded on one side - unfortunately there are several big holes in the plate so the linear rails can't be mounted directly on it.