Rat Rig Community [Unofficial]•2y ago

PWN not working on new fan.

Ordered a new fan, might not have been careful enough in my selection: https://www.digikey.ca/en/products/detail/cui-devices/CFM-4028BG-1160-520-22/16582008?so=80450973&content=productdetail_CA I had a 4028 fan that came with the rat rig running well on a BTT Octopus 1.1 with I guess standard configuration, red and black going to 12V always on and blue going to fan_controller_pin...worked well for a while, but I was just careless and fried it. Ordered this one. When I have the red and the black plugged in it runs at 100% all the time, but when I plug the PWN in it turns off.
This is what I've been running in my config [fan] pin: !fan_part_cooling_pin cycle_time: 0.00004 Fan seems to work well, just plugging in the PWN kills it, but when I unplug it it turns back on. Tried it on another printer (same board and setup) and same thing. I'm wondering if it might be cycle_time, but I I haven't been able to figure out how to calculate that.

13 Replies

miklschmidt•2y ago

So it won't react to PWM at all? It's supposed to turn off at 0% pwm. datasheet says pwm frequency is 20-30 khz, so 0.0004 should work the pwm pin on the new one you've got is the blue one as well It's possible that you fried your pwm pin on the fan port when you fried the other fan You can try another pin. Any gpio will do. Look at the pinout for the octopus and pick a pin then do: [fan] pin: !whatever_pin

wise-whiteOP•2y ago

I was worried that I might have ruined the port, but I tried it on the other printer and same thing happened. As soon as I plug in the PWM the fan turns off but it won't turn on when I turn the fan on I'll go try another pin though Welp, yeah...that did it! I don't know why it did the same thing on the other printer (unless I fried that one too 😬 )...but in any case, it seems to be working fine now on PD15. I should have tried that before I bugged you, but very much appreciated!

stormy-gold•2y ago

can i see your config? im having the same issue

wise-whiteOP•2y ago

[fan] pin: !PD15 cycle_time: 0.00004 That's the relevant stuff, you'd have to plug it in to the same pin obviously but nothing special really.

stormy-gold•2y ago

i tried that and i still get no response from my fan. its on 100% even at 0 and doesnt change no mater what pretty sure i have it pinned the same way also alright so i got it to respond but it only has 2 speeds...0 or 100.. if i set it to 20 its blows full force any clue on how to fix that?

miklschmidt•2y ago

try