Sadly, I am not able to "repair" my 3D printer. Every time, I want to print something that takes a bit longer to print, the extrusion stops at some point during the print (the first few layers are great), no under-extrusion whatsoever before that critical point.
I already tried temperature variation (185-220 °C) with about 5 different brands of 1.75 mm PLA.
I tried printing without any retraction, but failed (I also experimented with flow rate a lot and calculated the perfect percentage etc.)
Everytime a print fails, it is a nightmare to remove the PLA filament from my Bowden tube (because it expanded near the nozzle and is stuck in the Bowden tube). I have to pull with so much force, that I already cut myself several times because I slipped off my pliers.
As I know for sure (I already wasted almost 1kg of PLA for my testing) the problem is heat creep = heat travelling from the heat block to the PLA above because the heat break or fan seem to be broken.
So my question is: "Will it be enough to buy a new cooling fan (as the standard fan doesnt seem to be powerful enough)?"
I have to add that I already bought the original hotend long time ago and I tried printing with the "fan of the first hotend" and with the "fan of the second hotend" (the fan that blows air towards the cold end) so that might not be the problem.
Or do I need a totally new hotend? (with heatbreak etc.)
My printer is a Creality CR 10, and I'm using Ultimaker Cura 3.6.
Or is it enough to buy a new heating block + heat break? (I don't know if the cooling fan is the problem or the heat break).