unexpected warping caused by firmware change?

[printrboy]

what result does that fan serve?

[richardphat]

To actually cool as soon as possible and to prevent warping in the printing layer. It is an example where you can have PLA warping stupidly just as much as ABS. The time spend on the print layer is too short, that layer is just still too hot and does funny thing.

I feel this fan is much more situational though, it does more harm than good. If you want to print like small objects with thin wall, that fan will be use frequently. But that being said, if that fan is on without having a brim, it's pretty much guarenteed to have bottom warping.