Extruder is used in FDM or FFF technology 3D printer, which is known to everybody involved in 3D printing.

Extruder stepper motor is responsible for feeding filament and controlling the movement of filament to melt in hot end and then coming out the hot end’s nozzle a thin thread of melted plastic.

Stepper motor can affect printing quality in a number of ways.

  • Holding torque      
  • Resolution        
  • Step Accuracy  
  • Temperature rise
  • Vibration

Holding torque – normally, stepper motor with higher holding torque have a higher working torque at low speed. Higher working torque can guarantee enough power to pull filament spool to feed filament to extrude without delay.

Holding torque – it can lock the position of extruder during interval of printing process.

So, higher holding torque can avoid have a small gaps in start of print layers.

Stepper motor with higher holding torque is not a difficult thing. Lot of stepper motor has higher holding torque but, they achieve this by bigger motor size or higher current. Bigger motor size will make extruder bigger, and higher current will result higher temperature rise in clod end, which requires more cooling capacity to get temperature down.

MOONS’ is different with other brands as follows:

MOONS’ is different with other brands

MOONS’- MS17HD2P4100 has 0.48Nm holding torque at motor size of NEMA17 and lower rated current required.

Resolution – resolution means the minimum turning angle of stepper motor can reach, which is called Step-Angle. Mostly widely-used Step angles are 1.8 degree, 0.9 degree. Micro-step can be used with a micro-step driver If still want to improve the resolution.  Micro-step means that filament movement could be controlled in a very tiny increment, then, printing quality will be better.

Step Accuracy —- Step accuracy reflect real positional accuracy, the higher step accuracy, the higher printing quality.

Temperature rise – it is the same as mentioned on above.

Vibration – stepper motor run at a low speed around of 100-200mm/s, equal to 50-100RPM in a printer, may have higher vibration and it will effect on printing quality. By using micro-step driver or adding damper on stepper motor will help to reduce vibration.  

After replacing an existing extruder stepper motor on i3 MK3 with MOONS’ MS17HD2P4100, Prusa (the 3D printing company) website has comments that MOONS’ motors do run quieter and cooler, and can supply more torque for a given amount of current. Given the issues with extruder heat creep, replacing the extruder motor only would be best “bang for the buck”. Thank you Prusa for the test and let people know the benefit of MOONS’ motor.


We, MOONS’, would like to recommend following motors to help improve printing quality.

BrandModelHolding TorqueRated CurrentFrame SizeStep AnglePhaseMotor Length
MOONS’MS17HD2P41000.48Nm1ANEMA 171.8°239.8mm
MOONS’MS17HA2P41000.39Nm1ANEMA 170.9°239.8mm
MOONS’MS17HD6P41000.63Nm1ANEMA 171.8°248.3mm
MOONS’MS17HA6P41000.53Nm1ANEMA 170.9°248.3mm
MOONS’17HC6003N0.46Nm0.82ANEMA 171.2°343mm
MOONS’ML24HC4P31500.72Nm1.5ANEMA 241.2°345mm