Case fan

Bear with me, arduino newb here.

I put my rambo in a case. Really neat thing I found on thingiverse, but things got pretty warm. Before I go start fiddling with stuff, I don’t see the references to fan 0 or fan 1 in the marlin config than linked to. All the reading I did makes it seem to me that they are enabled by default, and I wonder if fan 0 blows all the time like on my ender hot end, or only when it thinks the extruder is heating.

Ideally, I’d enable the controller fan, but I get the impression I need to use fan 2, and I have a laser coming next week. If I understand correctly, I need to use fan 2 for that, since I’m on fusion 360 and using that post processor. If I could assign that to some other pin, that’d be great.

It’s only a 40mm 0.1 amp, so I could probably jump off the power supply, but I’m trying really hard to not be a hack.

While I’m at it, is there a clear explanation somewhere about how to figure out which board pins are which digital pins? I get that analog vs digital start from the same number, but I’m on lesson 4 with my arduino starter kit, lol. I’m having trouble understanding how to coordinate where I want things to happen with where the arduino is going to tell things to happen.


Wire it to the main power supply. Simplest way and no need to worry about how to turn it on. I did it this way. Not a hack in my opinion.


Do this.

No need to automatically control the cooling fans for your controller case, unless you’re a masochist! :wink:


Well then, that’s the way to go! Thanks!

Don’t forget the fan blows on the bottom of the rambo! All the stepper drivers use the pcb as a heatsink.


@Barry99705 You mean the fan blows to inside the box over the stepper drivers.

He is saying that the air needs to circulate under the rambo. the pcb is where the heat is.

I am not sure it matters too much, since getting fresh air in there is most important, then getting directly at the drivers. Getting it on the right side (bottom) is useful, but not a huge deal, IMO.


Thanks Jeff, I think going air is important…

I modified an existing case on Thingiverse to add a fan to the top of the case on my mini-rambo.

I plugged it in to fan1 (you could use fan0). I added a startup.gcode file that I use in the Guffy PP on F360. The last command is to turn on the fan. The Marlin command I use is:

M106 P1

By not giving it a S value, it defaults to 255

My Remix for the case I used is here:

The fan provides just enough cooling to be effective. My understanding is these boards don’t get that hot to begin with.

As Bryan said, wiring it straight to the power supply will make it on as long as the board is on. That’s what I do with my case fans.

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My power supply is 12V. My fan is 5V. The fan power wires wouldn’t reach the power plug and I was too lazy to find/build an extension, so…

Software solution it is! :slight_smile:

I do have some 60mm 12v fans from the last case I had. I may modify the lid again for the larger fan and run that off of the power supply. The last controller was a RAMPs and I had 2 60mm fans blowing on it to keep it nice and cool.

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There were issues with some of the first rostock max 3d printers with the drivers overheating because the fan was blowing on the top of the board. Later updates to the case has the fan on the back side, which fixed the overtemp issue.

Interesting. I haven’t had a problem on my mini rambo pointing at the top.

I don’t know, that’s just what was happening. The cases originally didn’t have the best airflow. May have been older versions of the rambo too, that was several years ago.