Replace Hotend fan with noctua  

RE: Replace Hotend fan with noctua

Posted by: @webstivi

Hello Everyone,

 

did anyone know, if it is possible to replace the default hotted fan of the mini with a silent noctua one?

(Noctua NF-A4x10 5V)

Thanks a lot!

Hello,

the Mini fan has this specifications: https://www.digikey.at/product-detail/de/delta-electronics/AFB0405VHA-A/603-2148-ND/9478065

Compare it with your noctua fan.

RE: Replace Hotend fan with noctua

So, noctua fan is installed.

only one problem:

fan needs a mechanical „tip“ to start rotating 🤔

after this, the fan runs continuously.

RE: Replace Hotend fan with noctua

@webstivi

Did you connect the fan correctly?

RE: Replace Hotend fan with noctua

@karl-herbert

Yes, I think so. Blue to RPM, Black to Minus and Red to Plus.

On startup if the printers the fan starts rotating without any problems .

RE: Replace Hotend fan with noctua

@webstivi

I have not tested it first hand. But as I have said to another member here according to specifications it looks difficult to replace the fan with a noctua.

As I said I have not tested it myself yet but look at the characteristics here.

https://forum.prusa3d.com/forum/hardware-firmware-and-software-help/mini-heat-block-fan-replacement-pwm-and-voltage/#post-190601

RE: Replace Hotend fan with noctua

Do you think this one would work? Specs are similar, rpm 8300 and 10 CFM. Might be just enough to keep the hotend cool while printing ASA and the like.

https://www.digikey.com/product-detail/en/cui-devices/CFM-4010-03-20/102-4398-ND/6194962?utm_adgroup=DC%20Fans&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Fans%2C%20Thermal%20Management_NEW&utm_term=&utm_content=DC%20Fans&gclid=CjwKCAjwr7X4BRA4EiwAUXjbt7z9szkQ0NFe9mXGkj7720Vk6i3VbSVI24yc2xdK9bG8p4Gd1Icb7RoCDuwQAvD_BwE

RE: Replace Hotend fan with noctua

@atchleyj

If the Noktua does not start on its own, it could be faulty. I had that once and exchanged it. With a voltage of 5V the fan should run in any case.

RE: Replace Hotend fan with noctua

same problem, fan starts only after a little finger tip.

Could this fixed in the firmware?

RE: Replace Hotend fan with noctua

There is a feature in the Marlin firmware to "bump" the fan to 100% very briefly when starting (all configurable) that might work. I have no idea how similar the Prusa Mini firmware is.

RE: Replace Hotend fan with noctua

@bobstro

somewhere in the source I found these snippets

case PIN_FAN1:
//hwio_fan_set_pwm(_FAN1, ulVal?255:0);
//_hwio_pwm_analogWrite_set_val(HWIO_PWM_FAN1, ulVal ? _pwm_analogWrite_max[HWIO_PWM_FAN1] : 0);
_hwio_pwm_analogWrite_set_val(HWIO_PWM_FAN1, ulVal ? 100 : 0);
return;
case PIN_FAN:
_hwio_pwm_analogWrite_set_val(HWIO_PWM_FAN, ulVal ? _pwm_analogWrite_max[HWIO_PWM_FAN] : 0);
return;

What if I change the code for FAN1 by setting a value _pwm_analogWrite_max[HWIO_PWM_FAN1]  (0xFF) ? -> needs to test

On the other hand: there will be a new fan management in the next firmware release 4.3.0 which could solve the problem.

RE: Replace Hotend fan with noctua

Firmware 4.3.0-RC1 fixed this problem, the Noctua fan is working now.

No other problems detected so far.

RE: Replace Hotend fan with noctua

As far as I know both FANs a re PWM controlled. 😉 

When you look at the fan test on 4.3.0 RC1 in fantest .txt file you can see at which PWM value what RPM the fan is spinning. The fans are controlled by fanctl.cpp. 

Not sure the Noctua will bare the same RPM than the original hotenf FAN.  What I read from Datasheet its max RPM is 5000, the max speed of the default hotend FAN 8 800 RPM.

To get correct RPM measurements the FAN should be four segment Brushless (2 north and 2 south poles) motor. On the picture is the principle, anstarct please the voltage.

.

RE: Replace Hotend fan with noctua

Seems the issue exists furthermore 🙁

the fan only rotates at a low speed, which leads to overheating of the throat and interruptions in the filament flow.

I guess I must order a new fan from Prusa direct.

RE: Replace Hotend fan with noctua

Posted by: @uh

Seems the issue exists furthermore 🙁

the fan only rotates at a low speed, which leads to overheating of the throat and interruptions in the filament flow.

I guess I must order a new fan from Prusa direct.

 

Thats a shame I was thinking about putting in the Noctua, my new mini the fan is bad, they are sending a replacement.

RE: Replace Hotend fan with noctua

@raymate

I tried a modified firmware with a higher fan speed for the Noctua, but it didn't solve the problem. I suspect the performance of the Noctua fan is too low.

Everything works again with the original fan.

RE: Replace Hotend fan with noctua

Like I stated above it is not the FW issue but the Noctua max speed issue believe me. 😉 

RE: Replace Hotend fan with noctua

@zoltan

Yes, I do  😏 

RE: Replace Hotend fan with noctua

Good information.  I have been contimplating fan replacement.  I have a noisy one.  I just ordered a replacement from Prusa.  

RE: Replace Hotend fan with noctua

@cwbullet

Well, the original fan is louder than the Noctua, but it works