I have recently started having problems printing 45deg overhangs and in general the overall print quality has deteriorated.
An image of one of my attempts is attached .
The model is 20mm square and about 15mm tall with one of the Y legs at 30 degs and the other at 45degs. The 30 deg leg prints OK.
I have carried out the following checks
Commanded the extrusion of 50mm of filament and it extruded 49.
Checked extruder temperature from 100C to 200C and good correlation.
Printed at various temperatures from 190C to 220C with little effect.
Changed filament to one which has in the past printed well and whilst there is an improvement it's far from satisfactory.
I recently fitted a Mk 8 extruder and it extrudes smoothly, the fan operates whenever the machine is switched on.
If i watch the printing of the 45deg leg it seems to turn up and then the extruder re-melts it and presses it back down.
The printer is a Mendel 90.
I'm out of ideas.
Any help appreciated