So I was thinking about is it possible to reach higher resolutions with encoders and DC motors? I found a cheap high-resolution magnetic encoder that can be used along with a DC motor to access higher resolutions. The encoder has 8192 PPR meaning that it can measure up to 0.04 degrees if I have correctly calculated. So if for a stepper with 0.9 step angle and no micro-stepping with 20 tooth pulley and 2mm belt, the steps/mm is 10, it means every 9 degrees with this pulley and belt setup makes 1mm and so 0.04 degree makes 0.004mm movement that is about 4 microns. Is this correct and possible? If so, why don't big companies use this method?
Link to the encoder: RLS RMB20 rotary magnetic encoder module