Different kind of stringing issue
I'm seeing a completely different kind of stringing issue. This is while printing PETG(Sunlu Gray), single extruder as in no tool changing. I made a simple three tower object and using the material preset for generic PETG as a starting point I then printed a series. The first two prints with the most stringing between the towers is at 235C. The most forward is with the original preset setting for Retraction. The second which is the next up in the pic increased retraction from .5 to 1.75 with the speed increased to 50. As you can see there is no difference between the two even with the significantly different retraction settings.
The next four each used the last retraction setting but I decreased the extruder temp in the following order; 230, 227, 225, and the top last at 220. As you can see in the pic the stringing abated as the setting was cooler. Each of these prints had optimal layer fusion. I tried breaking a tower off after each completed and each had the same fusion strength as the original at 235C.
So... without a calibrated temperature probe.... IMO based on this test, the extruder's heater is NOT calibrated. ALL the temps are WAY hotter than than what the settings indicate... by quite a bit! Anybody have a temp probe to test it???