Silly Question: Do Hot ends expand?!

[MiniMadRyan]

A bit of a silly question here. Like many of you, I have ABL set up and working fantastically on my i3v, but I've noticed something strange with my offsets.

If I'm in a rush, I usually bring the extruder and heat bed up to temperature as quickly as possible, and hit print. Usually in these cases when I do so, my first layer is a bit too high, it works, but it's not the best.

However, if I bring my extruder and heat bed up to temperature, and leave them to let the heat sink in for 10-15 minutes, then my first layer is spot on, perfect.

My question is, do hot ends expand slightly in height, or what's going on here? I would have thought, that if the bed was expanding, then I still wouldn't have noticed it, as the distance from the hot end to ABL probe wouldn't change, but it seems like the hot end, or something expands ever so slightly to affect the offset distance between the nozzle and ABL probe....anyone else noticing this?



Ryan

[TopJimmyCooks]

short answer: yes. most people do their calibration and abl after the bed and hotend are at printing temperature for this reason.