Add heat sink or fan

Hey there,

Monitoring my Mox (AGFC), I concerned about its heat : around 80°C most of the time. It gets warmer when I massively use the Wifi until it crashes.

Therefore, I’d like to find a solution by adding whether some heat sinks or somehow a fan. Thing is I’ve no idea how to do it.

Any hint ?


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Glad you opend this thread as my MOX PAB(WLE1216v5-20) crashes after short uptime and I am pretty much sure this is because of the WLE1216v5-20 getting very hot and the MOX having a very bad thermal air flow design for a passively cooled housing.
There are two options we can test: manually reduce thermal flow inhibiting plastic walls inside the housing. If this doesn’t help we can place a USB-fan to one end of the MOX. If this still doesn’t help (what I don’t think even in your case), the case needs to be modified another bit to directly blow air with this fan inside.
I’ll do the cutting of the internal plastic walls this evening and will provide pictures of it.

I guess you may be interested by this blog post.

Right now I’m running a 40x40 Noctua USB fan inside my Mox. It lays without screw or glue down the MIMO wifi card of the Mox A module. Temp is now around 60°C when the charge is at its maximum. Things are pretty stable and I’m no more worrying by the heat. Well, it works !

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Unfortunately I’m not that firm with soldering (what the guy in your link did), therefore I wanted also to go with USB - would you mind sending some pictures how exactly you did it and a link or the exact name of the model you use?
My plan is to cut the side plates from the top plastic units. I do not know if this is feasible for bigger MOX configurations in terms of stability, but it should work well at least for a 2-3 modules-configurations.


I am right now doing a measurement (therefore the pictures from my second MOX above) with my assembled PAB(WLE1216v5-20) and will compare after the modification, if this might be just enough.

Actually I’m using FreeCAD and my 3D Printer to edit the Mox case. I’m adding a hole one the top cover to glue the fan over the heating parts.
Let me know if you have a printer. I’ll send you the edited parts to print.

No, unfortunately not. That would have eased things a lot :wink:
I just finished cutting/melting and am now running a second “normal evening”-test. But even though I own a industrial-version of WLE1216v5-20, it get’s to hot in my eyes (after 15 minutes of excessive youtube/instragramm-usage of my wife’s SGS8 - only this device connected):

root@turris_AP_OG_1:~# sensors
Adapter: MDIO adapter
temp1:        +85.0°C  (crit = +100.0°C)

Adapter: PCI adapter
temp1:        +88.0°C

so it’s obvious I absolutely need an active cooling solution.
I read the Noctua is the favorite for 3D-printing - or did you really just glue to the printed top-cover? Do you use the PoE-module? How hot does your MDIO get (I believe this is the MOX’ CPU)?
~60°C is a good range for the MOX - I have a second MOX pocket-WiFi running completely stable at ~67°C.

Question is, if I should go with milling a 40mm hole at one of the ends (probably the one housing the PoE-module) and a 40mm fan (which one did you exactly use) for blowing air from one of the two ends to the other or milling a 40-80mm-hole on the top of the case and install a 40-80mm fan.

edit: I stopped the analysis 1h17’ after the “normal evening”-test ended because that single connected SGS8 (yet in sleep mode) lead to the following temperatures:

root@turris_AP_OG_1:~# sensors
Adapter: MDIO adapter
temp1:        +95.0°C  (crit = +100.0°C)

Adapter: PCI adapter
temp1:       +101.0°C

and will post some pictures after fan was installed.
@dadall maybe you could post also some pictures of your (perfect :wink: ) solution?

Heat sink + Fan is definitely better. Heat accumulates around like a cloud and doesn’t flow away itself easily unless there is enough air flow.

@ssdnvv Noctua is mainly known as an expensive but very good quality cooling stuff company.

I bought a Noctua NF-A4x10 5V PWM and a Noctua NA-FC1. The first one is a tiny USB fan and the second object is a controller I use to set the fan speed as low as possible so I can’t hear it. You don’t need it if you don’t mind the noise. You may not need it too if you have electrical knowledge to plug the fan directly to the Mox.

Two pictures of the installation :

As you can see the fan is in the Mox case to extract the hot air from the A module (+ PoE). It fits perfectly.
The fan is connected to the controller then to a USB port from the module F behind the Mox.

I need to change few things to hide the screws and re-print few parts with a better configuration to make the whole prettier.

I must say it works as expected : inside temperature is now bellow 60°C while fully charged (USB transfer, Wifi, ethernet, etc).

So : a hole plus a fan and things are fixed !


Two more technical questions (out of curiousity - thanks for your answers):

  • one of the few laws of air cooling: pushing cold air is much more efficient than pulling hot air. So why do you draw out the air instead of blowing it in? But anyways - if you with minimal noise (=minimum speed) reach 60°C, it really works. I am planning to blow it in as I believe the WLE1216v5-20 will not be adequately cooled from drawing air out (this was also advised from the blog post you linked above - yet they didn’t cut a hole into the housing). The question is only if I should go the direct way by milling the hole into the top cover or from one of the “mesh-like”-sides. Top would mean more cooling power but milling more parts, side would mean blowing from the PoE-module towards the WLE1216v5-20.
  • Why don’t you use a dust filter to secure your board from dust and insects? (Cheap example - there are also plastic- or aloy-nets available for a couple of additional Euros)

Thanks for the idea with the fanspeed-controller, I have an older one available that I will reuse for this project :slight_smile:

Thanks !

To be honest, I have no knowledge about air cooling so I asked around and people said that if you use one fan, pulling out the air is the best solution. I’ve been told that the Mox case do not allow a as-perfect-as-possible “blowing in” solution.
The pulling out solution allows the cold air to get inside the box by the two mesh-like sides which is pretty nice.

Here is a preview of the original “mox top” (left) and mine (right) :

Beside the holes, note that I removed most of the sides to let the air go through the box (don’t mind the artifact on the top left corner, this is an import issue not present on the final piece). That make me say that pulling the air outside may mean more milling for you.

Why I don’t use a filter ? 'cause nobody told me to do so before you ! :stuck_out_tongue:

Don’t get me wrong - I am simply curious why you chose that specific way.
Thanks also for mentioning also the NA-FC1, that is for sure a social-necessary part!
I’ll post my pictures as soon as I am done, but I can already tell that pushing air into the housing reduces the temperatures below 40°C at full load. I’ll also somehow experiment with replacing side pieces by dust meshs.