Extruder skipping after some time  

Extruder skipping after some time

Dear all,

I am having problem with my print. I am using PLA (green) supplied from the kit version. Usually the first layer will print well and extrusion rate is good. However, after the model gain height (I am printing the marlin from SD card), the extruder motor will start to skip and the filament will barely get extruded from the nozzle. The marlin will only be printed half way. I have checked the brass pulley is clean and the extruder motor is working fine. Its frustrating that when I check back the model after sometime only to realise that it is only half printed as PLA had not been extruded as the extruder motor is skipping on the filament. I try to unload and reload the filament and nothing is clogged.

The weirdest thing is when I try to print with ABS at 235 degrees, there is no problem with the extrusion and the motor doesn't skipped at all. In this case I am not printed the marlin model supplied in the SD card.

I am really puzzled and wondering what is really the issue.

Thanks in advance guys for helping!