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Cooling :: Blib fan to full power :: Avoid G4 P500

Posted: Mon Apr 22, 2019 7:45 am
by Brunibbels
In all Versions I know
-> within FFF Settings
-> Cooling
-> Fan Options

There is this checkbox which label is "Blib fan to full power when increasing from idle"

Why the option is needed:
This option is ment to kickstart a fan to a spinning state when commanding low rotation speeds.
Some printers do this by hardware but it is still possible to do it using software. Software means that we use M106 S255 for a short time and then M106 Sxx to reach the requested speed.

Using the described option Simplify3D inserts a G4 P500 which might result in printer stuttering and which breaks the print flow. Whenever the checkbox is unchecked no G4 P500 are inserted and the print is nice. Whenever the checkbox is checked the stuttering occurs. That does produce blobs and is likely to result in inconstend extrusion.

G1 X128.853 Y45.279 E1.4036
G1 X128.853 Y36.582 E1.4668
G92 E0.0000
G1 E-2.0000 F720
; layer 3, Z = 0.450
M106 S255
G4 P500

M106 S8
; feature outer perimeter
G1 Z0.450 F1002
G1 X99.900 Y45.078 F4800
G1 E0.0000 F720
G92 E0.0000
G1 X126.600 Y45.078 E0.1940 F2550
G1 X126.600 Y193.653 E1.2735
G1 X126.449 Y193.653 E1.2746

Please insert M106 S255 into the normal Gcode flow. I would just set the M106 S255 somewhere (time-)prior to the actual M106 Sxxx

- If that feature as itself is already deprecated and might be removed in future: Please add a warning if the checkbox is checked.
- Maybe split prior long movements into two short ones to gain the perfect a (time-)place to insert M106 S255 instead of using G4.
- A better way for cooler configuration might be a new menu where people can adjust the coolers 1% and 100% rpm as a translation of "pwm" to rpm.
Multiple pc mainboards deliver great examples for such a diagram. ... 20&thumb=1
Using such the definition of the fans control range that shows hysteresis might become easy.