Several years ago, bought an Ender 3 Pro. After making modifications (dual Z axis lead screws and Creality metal bed most note worthy), it was working fine for a long time. However, I recently started printing objects again, and I am having no end of bed leveling problems.
My leveling technique has been: heat bed and nozzle to temperature, position the Z axis to 0.1mm, position the nozzle over each adjustment screw (in turn) and using a 0.1mm feeler gauge adjust the leveling screw to have a slight drag between the bed and nozzle.
Printing up a test pattern of 9 squares, each 20mm square and 1 layer thick, the printing starts out fine but then appears to not stick to the bed. I have cleaned the bed using soap and water, alcohol, and some other (much) stronger solvents.
This all started after 19 hours of printing, all of which came out fine. Since then I have spent many hours cleaning, adjusting, checking for loose screws, check for squareness, and nothing seems to have helped.
I’m probably missing something simple, but I just cannot seem to see it. (I haven’t changed the brass nozzle for a while, could that be part of my problem?)
Thanks in advance.