Saturday 4 January 2020

Which problems do the stepper motors have

Not everything can be an advantage, stepper motors also have quite a few important disadvantages, lets go through them.

Very low efficiency
Yes, the stepper motors waste a lot of energy, compared to the traditional electric motors. Therefore, they consume more current than common motors.
They also consume their maximum when in rest, so they tend to reach high temperatures.
Nema 14 Stepper Motor Bipolar 1.8 deg 14Ncm (20oz.in) 0.4A 12V 35x35x26mm 4 Wires
14HS10-0404S

They are slow

To turn a full revolution, the motor has to step 200 steps, one step at a time. Therefore a common electric motor will always go faster. If you need speed, you have to invest in a servo motor (which are more expensive), or get your hands on a stepper motor with an encoder.
Nema 17 Stepper Motor Bipolar L=48mm w/ Gear Ratio 5:1 Planetary Gearbox for 3D Printer Extruder Motor DIY CNC Robot Rob

17HS19-1684S-PG5

What is an encoder?
An encoder is a device which allows you to know the real current position of a motor.
Low torque at high speeds
If on rest they are very strong, just the opposite happens at high speeds. They suffer the same problem as I do when I go for a run, I run out of steam really fast.

Feedback
They don’t provide feedback.
Unlike servo motors, the stepper motors do not know their position at any given time, and they cannot adjust themselves. Your only option is to build a system by yourself to measure and correct their position.

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