nozzle rubbing on infil Ultimaker 2+

[rayr 0]

hi there, model is Ultimaker 2 +

about 2 years old, about 300 hours of printing

just updates firmware but no difference

just replaced liner bearings that fit in the head

new nozzle 

printed at different speeds and different temps

mainly print with PLA but the same symptoms existed with PETG

i have tried various infill patterns 

 

the general symptoms are rubbing off the nozzle on infill when the head print head crosses previously printed infill on the same layer height

the knock on effect is the infill is not bonding correctly

 

i have googled this and it would seem that this problem does happen occasionally but i could not find any plausible conclusions 

 

many thanks in advance

 

Ray