Print that fails at the same point every time (advice please!)

Hi all

I have a print that i’ve successfully printed a couple of times.

Increased the print speed, and now it consistently fails at pretty much the same point every time with error “Heater extruder not heating at expected rate”! it’s on the last layer which is really small, so it’s not a massive issue, but…

My guess is that the cooling fan is kicking in since it’s a small layer, and the extruder is struggling to keep at temp with the cooling fan running? But i’d appreciate the views of more experienced people!

And if that is the case, what is the best option (short of not running the cooling fan at full blast, or upgrading my extruder!)

Thanks in advance!

log file attached:
klippy.zip (472.6 KB)

Hello @VaticanUK !

If the part cooling fan blows to the wrong direction, this could happen.
I’ll recommend the use of a silicone sock for the heater block. It also heats up a bit faster and it stays clean.

when you say “wrong direction” do you mean the fan running in reverse? Or just the output pointing in slightly the wrong direction?

Thanks - i’ll look at a silicone sock!

No, it does not only blow onto the part but also onto the heater block.