Having printed my first few models, I decided to ‘tweak’ the bed levelling, to improve some issues on the first layer. Unfortunately, that then caused me hours of head scratching when all of a sudden the PLA simply would not stick.
I played with the hot end and bed temps, levelling, z-home size, and a bunch of other things, and five failed prints later decided to give it a break. While watching an episode of Homeland I had the ‘aha’ moment - I was using screen cleaner to clean the glass bed, thinking that would give a nice grease free surface.
But in actual fact, it adds some kind of anti-finger print chemical. Using a bit of mild soapy water to clean the glass, and hey presto.
Two of the failed first layers - not sticking due to screen cleaner