Rat Rig Community [Unofficial]•6mo ago

4028 Fan weirdness

#fix-my-printer Bit of strangeness around my Delta FFB0412UHN 4-pin 12V 4028 fan. Its hooked up as documented here: https://os.ratrig.com/docs/guides/4028 It mostly works. 0% fan is off, 100% is jet engine. So far so good. But there are some strange things 1) It doesn't seem to come on until the percentage is about 7%. 2) the RPM (wired to PD14 ) is wierd. at 0%, its 0 rpm. at 50% its about 12000 RPM. But then it seems to DECREASE. at 80% power, the reading shows about 900 RPM, even though the fan is spinning WAY faster. Also really odd is that the ratrig article says that for delta fans, blue wire is PWM But https://www.delta-fan.com/Download/Spec/FFB0412UHN-SP4Z.pdf claims that the YELLOW wire is PWM, where Blue if F00. That document also states that 25 Khz is correct, leading me to believe that a cycle_time of .00004 is indeed correct. My fan section reads: [fan] pin: !fan_part_cooling_pin cycle_time: 0.00004 tachometer_pin: ^PD14 tachometer_poll_interval: 0.0005 Any suggestions? What kinds of parameters should i be looking at?

Connecting a 4028 fan | RatOS

4028 server fans are becoming a popular option for part cooling because of their light weight and great pressure and flow rates. In this guide we'll go over how to connect one and use it for part cooling. 4-pin fans usually aren't used in 3d printers, and many boards only provide 2-pin ports, but fear not! There's always a way.

3 Replies

Oskait•6mo ago

You can try to fix your fan not coming on below 7% with an increase in the kick start time, for example like this:

[fan]
kick_start_time: 0.500
#   Time (in seconds) to run the fan at full speed when either first
#   enabling or increasing it by more than 50% (helps get the fan
#   spinning). The default is 0.100 seconds.

[fan]
kick_start_time: 0.500
#   Time (in seconds) to run the fan at full speed when either first
#   enabling or increasing it by more than 50% (helps get the fan
#   spinning). The default is 0.100 seconds.

If your fan is running and then shutting down below 7%, then that is just the limit of your fan and it cant run lower

goofwithz3•6mo ago

yeah, nope. still 7%. I'd really like to figure out what is going with my rpms though...

Oskait•6mo ago

then 7% is probably just the lower limit of your fan. I dont have tach connected so cant you help there, sorry.

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4028 Fan weirdness