Thermal Fluctuation - How much is too much?
I've been dealing with an intermittent thermal runaway issue (extruder, not heatbed) so naturally as I make some adjustments I've been spending WAY too much time monitoring extruder temps. So my question is I think a simple one....I fully expect that the temp will fluctuate, but how much is "normal". I know what the thermal runaway parameters are, so I'm really asking for "normal" underneath the runaway threshold.
The swing seems to be about 5 degrees up/down, so is that working as intended, or an indicator of something that needs replacing or adjusting? Below I included a fairly typical trace of a PETG print from Repetier. The print is 8 small-ish pieces spread evenly around the build plate, with nothing in the middle.
The first longer trace is from the first few layers with the print fan off. The temp line is 240 degrees
The second trace with the big fluctuation is during the print fan portion. It wasn't right when the fan kicked on, so it's weird to me that it takes that big bounce (16 degrees down and 8 degrees up) before it normalizes.
Thoughts?
