Cooling Fan Use

[csimmons 0]

I have had this printer for a couple months now. I recently decided to run some test prints to dial in some setting and noticed a very poor quality on some of the prints. As I watched on print I realized that the cooling fans were not turning on during the print as they had in the past. I checked the settings for fan start up played around so that it should turn on after the second layer has been laid, but still have not been able to get the fan to turn on unless I do it manually from the "Tune" menu on the ultimaker LED screen. Is there a setting I am missing that would cause the fans to never turn on during a print?

 

[gr5 2,172]

Well if you can get the fans to spin with the TUNE menu then I suspect Cura isn't turning on the fans. Look at the gcode file that cura produces in any text editor (for example on a PC you can use notepad). gcode files are human readable.

Use the editor's search feature to locate all fan commands M106. For example:

M106 S127 <-- Sets the fan to 50% and

M106 S255 <-- Sets the fan to 100%

My fan doesn't come on until around 30% which is M106 S76. Your fan may vary a bit and need 40%.

In Cura I set my "fan min" and "fan max" both to 100%. If you set the fan min to 0% I believe it won't turn on unless the layer time is less than the minimum layer time.