PLA and creep (slow deformation over time)

[CaptainObvious]

I noticed that PLA seems to suffer from creep, the slow deformation of a material under load over time. Or at least I think it does.
For example the landing gear legs of a multicopter I've printed several months ago have noticeably yielded over time just by sitting inside a cabinet for that time.
Temperatures in my apartment can go up to 35 degrees centigrade, so that may be a factor, but the glass transition temperature of PLA is supposed to be 60C.

I wonder if that may be the specific composition/manufacturing of the PLA I used or if it is just the way that material behaves.

Has anyone noticed this effect on PLA (or other material) prints?

[Geoff]

I use ABS for quadcopters only, PLA shatters and has no flexibility I find and makes for a too rigid frame at high speeds, and also the fact that after only 1-2 weeks, I was finding the arms , lets say F450 size, max build plate for me anyway, were warping upward, even with the special 'non'warping' addidions to it.

My ABS quads, some over a year old are still flying without any warp at all, and it gets to 40 - 45c here.

[3DPBuser]

Yes some material can droop like that. Some materials can even be described as "supercooled liquids".