Upgrade MK4S > Core One +: Hotend filament sensor not (really) working
Last night I finished upgrading the MK4S to the Core One +, and after a few issues with the calibrations and self-test, it got printing and quite nicely. Happy there. But I keep having problems loading filaments. Although the side handle filament sensor is working fine, the hotend filament sensor really isn't. Even after opening the lever and looking in, the filament tip is there, so the sensor should be ON. But I can't load filaments unless I open the lever, push filament until roughly half way or more down the gears, close lever, and then it detects it. Is it just a calibration issue, or something bad with the sensor?
Important detail: the sensor is the MMU3 one that I had with the MK4S, but for now I am going to only be using the Core One + in non-MMU3-mode, until I am familiarised with the machine.
RE: Upgrade MK4S > Core One +: Hotend filament sensor not (really) working
And have you set the correct sensor type in the printer UI? The two types differ in function. The classic sensor works in such a way that when filament is detected in the sensor above the gear, it starts the extruder wheels to insert the filament into the nozzle, and the normal procedure for inserting the filament into the nozzle is started. The MMU sensor works in the opposite way. When filament is detected in the side sensor or FINDA on the MMU3, the extruder starts to rotate slowly and waits for the filament. If the extruder wheels catch the filament and start pushing it into the nozzle, the printer reacts to the filament pushing the wheels off the pressure segment. And only then is the filament detected in the nextruder, the slow rotation stops and the normal sequence of inserting and cleaning the filament in the nozzle starts. So if you have a filament sensor for the MMU, you must set the sensor type in the UI to MMU, otherwise the problems you describe will occur. And of course, it will also work with one filament without the MMU. I even threw away the original sensor when building the C1, printed the parts for the MMU sensor and mounted it on the C1 right from the start. The advantages of the MMU sensor are mainly that there are relatively large forces between the moving parts and the sensor does not react to small pieces of filament and does not clog, unlike the original type where only the force of a fine spring acts on the sensing needle.