Fan not running on brim?

[LePaul 354]

I am used to seeing the fan always running on my Ultimaker. Its doing a job now, no fan runninng.....normal? Its still doing the brim...made sure in Cura cooling fan is enabled.

 

[LePaul 354]

Oh....its running now....false alarm

 

[illuminarti 18]

The fan usually starts several layers into the print, so as keep the first layer hotter, to help with bed adhesion.

 

[gr5 2,265]

Also when the nozzle is close to the bed, the fan cools the nozzle more than normal. Cooling the nozzle can cause underextrusion.

The latest cura increases the fan very gradually (by default). I think so the PID controller can adjust a little bit after each layer so that the nozzle doesn't get too cold.

Once I went from 0% to 100% on a layer and got underextrusion for about 60 seconds.

 

[LePaul 354]

I haven't upgraded Marlin since the printer arrived in September.