Fans and ambient temperature  



I have my Robox Dual next to my desk, and assume many others have it somewhere close to their workstation as well, and was just wondering if it's supposed to make as much noise as mine is doing now. I think the majority of the noise comes from the fan on top, that seems to run at max continuesly during all prints regardless of material or ambient temperature settings, and I'm not sure if it's always been like that or if it's changed at some point in time. I do suspect it's not always been like this since I used to be annoyed by the stepper motors and bed resonance, but now I can't even hear that because of the fan noise.

I've also noticed that for some filaments, like TitanX, the ambient temperature is set very high (60 degrees I think?), but never seem to climb above 30 or so. If the fan is running faster, or more frequently than it should, I assume these "issues" could be related?

This topic was modified 7 months ago by Espen Johannessen

I just found another forum thread mentioning a similar issue, and the user was asked to run M105 to check if the system reads fan speed correctly, so I tried running M105 duing Home when the top fan was running at full blast and got the following result: "S:28 @0 T:29 @0 B:35 ^0 A:29 *0". If I'm reading this correctly I assume it's correct that the head fan was not running, but the top fan was definetly running and seem to report back 0 RPM?

The top fan exhausts the print volume. If it is running constantly when the printer is on, the mainboard has been damaged and you can either deal with it or open a support ticket. If it only runs during a print, this is correct behavior. 

2 Answers

It only runs during prints (and homing and a few other scenarios, but I assume you ment if it always runs when power is connected?), but as I mentioned it runs at full blast all through the prints (and the other scenarios mentioned). Is this normal? And if so; is it also normal that the ambient temperature never exceeds 30 degrees even when the settings says 60? The temperature in the rom is normal at around 21-23 degrees.

I see that the fan ambient and ESC fans only has two leads, so I assume no RPM feedback for those fans and that the fan is controlled by temperature alone?

No RPM feedback, and it sounds like the control MOSFET may be damaged. I would open a ticket.

OK, I'll do that. Thanks BHudson!


This is the description page for the M105 command Espen refers to.

Ambient temperature threshold is set using M170 command

From this page

M170 - Set ambient target temperature [S] S=Override Temperature °C . This command sets the ambient temperature using data supplied from the reel EEPROM. [S] provides a manual override for custom temperature. e.g. M104 will set the ambient temperature to the value stored on the reel / previous value sent, M170 S35 sets it to 35°C.

eg the following command entered into the GCODE window and sent to the printer

M170 S60

will set the system so the ambient fan will extract the build chamber to try to keep the temperature below 60°C.

The sensor is just behind the head at the bottom left on the rear of the gantry, it is visible just below the finger wheel.

In some cases as suggested in the comments there may be a fault in this control, the support team can advise on this.

For official support please create a support ticket using this link

Hi Pete, thank you for the description and additional information around fans and temperature! I also posted a question on the unofficial Facebook-group and luckily Charles Jackson pointed me in the right direction: the cables for the electronics fan and ambient temperature was switched. I had my Robox in for repair almost two years ago (!) and after a heatbed and motherboard swap the local supplier must have connected the wires wrong when putting it all back together!

I am kinda ashamed for not figuring this out sooner, and just assuming my Robox had gotten loud and unreliable with hard-to-print-materials over the years, but when all is said and done I'm just happy to have it working as it should again. Had yet another TitanX failed print a couple of days ago, so I'll re-print the same gcode again and hopefully this time everything comes out looking pristine!

Thanks again and a quick shout-out to the unofficial Facebook-group and mr. Charles Jackson!


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