Fan settings in Cura for UM2

[schafe 3]

I recently forgot to turn off the fan for an ABS print.  As the print progressed, the fan increased speed as the file instructed it to.  When I turned the fan speed to 0, it returned to the programmed speed after a few seconds.  The only way I could keep it off was to keep the fan speed screen active and set to 0.  What am I missing?  Other settings like print speed or flow % don't get rewritten after I change them.  It has been a while since I updated the firmware on my printer.  Is that it?

 

Thanks

[tinkergnome 924]

That's a normal behavior. Fan speed is an absolute value, it will be set opnew every time the gcode contains a M106 command (the last one wins...)

The fact that the value from the file is overridden as long as the menu is open... well that's probably just an accidental side effect.

 

Print speed (on the printer) is an (additional) percentage setting, this behaves different and just multiplies all speed settings from the gcode file with the chosen factor.

 

[schafe 3]

I experimented with the fan speed again last night and am now more confused.

 

Sure enough, when I set the speed to 75% when the program wanted 20% after a few seconds it went back to 20%. 

 

Now my question is, if the speed a user selects on the UM2 controller is constantly getting overwritten by the gcode, why is fan speed even an option.  Kind of gives the operator the false idea that he/she has control over something they really don't.

[danielkrice 4]

Jumping in on this post slightly but also experiencing a similar issue to above and after a bit of help - I'm struggling to understand how the various fan/cooling settings are linked and which takes priority. So...

• Under material profiles, printer settings you can set fan speed to a % value.
• Main side bar, under Cooling - You can enable fan cooling and fan speed again, which is also a % value.
• ChangeatZ plugin, fan speed is labelled as a PWM value (0-255).

I'm trying to print with ASA filament but I'm struggling with it atm so if I try a test print, changing the temp and fan speeds, how should I have Cura set up?

 

Material Profiles - 10%.

Cooling enabled and fan speed matches profile so 10% Max (2% Reg).

 

However, with these settings the fans don't spin - Is there a minimum % I need to enter?

 

Then if I do use the ChangeatZ plugin, how will the values I enter here effect the % settings?

 

Running tinker on a 2+.

 

Many thanks,

[schafe 3]

On my UM2 the fans require a set point of 25-30% just to begin rotating.  Once they start to spin, they will stay spinning down to about 10%.  I think it is a limitation of the physics of the motors, etc.  I figured this value out by controlling the % on the printer during a print.