The extruder is the first thing I changed on a prototype of my 3D LAD-1.0 printer. Bought on "Ali" MK8 obviously did not cope. The clacks of a stepper motor forced the temperature of the nozzle to rise above the optimum and reduce the performance of the printer. Pro printing with a nozzle of 0.3 mm could not even be considered. The 52 N * cm torque of the 17HS8401 stepper motor was not enough for a gear roller with a diameter of 11 mm. In addition, there was a tendency to the filament wringing due to the large distance from the toothed roller to the inlet of the bowden tube. Therefore, I decided to make an extruder with a reduced roller having a diameter at the tops of the teeth of 7.5 mm, which promised an increase in the force by almost 1.5 times. This extruder has worked for me more than 1000 hours no problem. The design proved to be balanced, the traction ability of the engine and the toothed roller were almost equal. Filament wringing did not occur, refueling is quite convenient. As a result - only 20 grams of filament and the problem is solved. References: https://3dladnik.wixsite.com/portfolio/extruder-en 3Dprinter Lad-1.0: https://3dladnik.wixsite.com/portfolio/lad-1-0-en