PP3DP, makers of the popular Up! personal 3D printer announced they’re upgrading their filament feeder in a significant way. Their original feeder involved a DC motor and mechanical switch, which limits the accuracy of prints as the DC motor takes a while to start up and spin down when electricity is applied. This means you’re not extruding immediately when you start printing and you don’t stop extruding when you should stop. The quality of the print suffers slightly because of this.
However, the new version of the feeder will include not only a stepper motor to replace the DC motor, but also a micro switch. This should significantly improve the quality of prints.
Most of the personal 3D printer makers have now switched from DC to stepper motors for extrusion, and all have had terrific improvements in quality. We’d say this is now pretty much a standard if you want to sell a 3D printer.