Plug simple stepper motor NEMA 17 on E2 slot of the main board on Creality CR10 I have build a Syringe Pump with a simple stepper motor (NEMA 17), and now I want to actuate it through my 3D printer. I successfully replaced the main extruder with it and it worked, although I had to still warm up the hot end as Marlin doesn't want to actuate the extruder at cool temperature. Anyways, I am realizing that my Creality CR10 v3's board has a slot for a second extruder, so I would like to plug the syringe pump there. I did it but when trying to control it through OctoPrint, I have an error saying that my printer reported a default. I guess it's not plug-and-play, and it's probably complaining about the absence of second thermistor and so on , right? What should a complete newbie like me do to be able to control E2 with just a stepper motor connected to it?

To prevent extrusion at cold temperatures, you should enable the feature called "allow cold extrusion" using G-code `M302 S0`.

Using a spare stepper slot requires building new firmware and uploading it to your board. The most obvious choice is using Marlin firmware, as this is the software that runs on your current board. You need to add an extra extruder in the configuration file.