part cooling fan PWM issue

[daduke]

Hi,

the Sunon EF50152B1-1C01C-A99 isn't a very good choice as a part cooling fan in this configuration due to its BLDC and autostart function (the A in the part number). With the given configuration, the fan is basically off (< 99% fan setting) or running full blast (>= 99%). This doesn't really make tuning part cooling possible. The best workaround I found is to drive the fan at a very high (hardware) PWM frequency:

[fan]
pin: EBBCan:gpio13
kick_start_time: 0.1
cycle_time: 0.000025 # 40 kHz
off_below: 0.07
hardware_pwm: true

but even then, the lowest possible fan speed (7%) is quite high.

best,
-Christian

[Pneumanifest]

Can confirm. The part cooling fan will not allow for much tuning if at all.

[daduke]

I replaced it with a GDStime 24VDual Ball 8500RPM which gives me full 4%-100% power range.