I'm running Felix 1.5 with added LCD/SD expansion. As I monitor the extruder temperature during a print it stays constantly ~10 degrees too low. So, if I set extruder temperature to, say, 205°C, the actual temperature swings around 192-197°C but never reaches 205°C. If I drop target temperature to for example 195°C, actual temperature stays around 180-190°C. Why is that? If I set temperature higher (like to 220°C) it can reach and keep higher temperatures than 205°C with ease. It looks like a controller logic/code problem or poor tuning.
There are some settings in the LCD menu for temperature control but I don't quite understand them. Any ideas how to make the temperature more accurate? I'd rather have it swing between 200 and 210°C if I have set it to 205°C rather than between 190 and 200.