UM2+ requires manual bed levelling for every print

[lowracer 0]

I have four UM2+ bought in 2016 used in production on a daily basis. They used to hold a bed level setting for weeks.  

 

Now I have to go through the manual bed levelling process EVERY time I print.

 

This morning was the last straw, I levelled the bed, printed a bed level adjustment test pattern, manually adjusted the screws so that test pattern was perfectly level and with the right "squish." After removing that test print I immediately submitted a print job, and the nozzle was scraping the glass! Immediately, no cool down, literally seconds after manually getting the bed perfectly level. This is plaguing all four machines.

 

Any suggestions?  Do these machines fall out of calibration after a few years of hard use?  

[ultiarjan 1,221]

Think my oldest Ultimaker2 is from the beginning of  2014... still going strong...

 

Sounds to me like a mechanical thing, did you check all the screws and springs? maybe tighten the springs more?

Just make them pretty tight, but be carefull to keep a bit of space between the power connection block (back left) between the bottom plate and the heated plate.

 

As you mention it's on all 4 machines, common sense dictates that is likely something in your workflow, and not the machines... did you change anything in your way of working with the machines?