Hotend Fan Issues
Hello,
Did anyone else encountered a problem where the hotend fan just stops or throttles down mid-print or mid-calibration? It usually resumes the spinning just right after that. On one cccasion after a print finished, it just stoppen when the hotend was still 160 degrees celsius = so the temp sensor is OK.
A reset not but turning the printer off, then on again helped.
The fan is quite new, must be 3 months old.
Here are 3 videos: just listen to the sound, you can hear the hotend fan throttling down and then resuming normal operation.
---> Seconds 7, 12, 21, 25
---> Seconds 7, 23
---> Seconds 3,17
Re: Hotend Fan Issues
Never mind, just figured it out: it's a cabling issue. Wiggling the cable tree behind the extruder reproduces the exact issue.
Re: Hotend Fan Issues
Check if the temperature of the hotend also changes when wiggling on the cable tree. If so:
I had a similar behaviour. The extruder didn't extrude any more material and the hotend fan was oscillating because the Rambo thought temperature is too low. By the end the reason was a bad crip connection within the plug of the thermistor and the extension wire which sits within the extruder assembly. I got rid of that plug and soldered the wires together. No more issues since then.
The spare thermistor Prusa sent me already had the wires soldered to the extension wires. I'd say that this indicates that there is/has been an issue with that connection.
Re: Hotend Fan Issues
Never mind, just figured it out: it's a cabling issue. Wiggling the cable tree behind the extruder reproduces the exact issue.
That is something which happens occasionally (only happend to me once so far).
Just behind the extruder, where the cables bend 90 degrees to enter the bundle. Stresses due to continual movement.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Hotend Fan Issues
Printing the new MK2S extruder now. Figured if I have to take it apart, I might as well upgrade it to the newest version.
Re: Hotend Fan Issues
Hi,
I have slightly different issue with the hotend fan - it is LOUD. As soon as hotend temp. reaches some point, fan starts to spin with max speed and it is annoing. Is it normal or maybe I'va made a mistake while assembling my MK2S?
Re: Hotend Fan Issues
Hi,
I have slightly different issue with the hotend fan - it is LOUD. As soon as hotend temp. reaches some point, fan starts to spin with max speed and it is annoing. Is it normal or maybe I'va made a mistake while assembling my MK2S?
it's quite normal that the fan that cools the coldend (the one that's mentioned here as hotend-fan) starts to spin at full speed when a temperature of 50°C is reached. there is no speed control for this fan. just on or off.
and, because the fan needs to shovel approximately 4 cubic feet of air per minute, to keep the temperature of the coldend below 50°C, it might produce an annoying sound.
the intensity of this sound vary for the different brands.
dem inscheniör is' nix zu schwör...
Re: Hotend Fan Issues
Found it: a soldering joint was the culprit
Re: Hotend Fan Issues
Hummm. There should not be a soldered joint there.
That is on the assumption that the fans supplied are from E3D - their fans come with a very long cable.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Hotend Fan Issues
Hummm. There should not be a soldered joint there.
That is on the assumption that the fans supplied are from E3D - their fans come with a very long cable.
Peter
I know. I got 2 fans as a replacement earlier, this one is soldered, the other one is not.
Re: Hotend Fan Issues
Have to say, whilst it's more of an E3D problem than a Prusa problem I'm surprised that the Stock E3D fan wasn't or hasn't been addressed.
Whilst there's not a cataclysmic failure rate, there are enough stories on this and other forums to suggest the QC of the E3D fans isn't the best.
My own fan failed (sporadic on/off so not easy to identify initially) out of the gate causing a couple of pretty serious jams which destroyed not only the PTFE liner but the quick release gasket thingamabob as well.
Perhaps something Prusa could look into for the MK2SX revision 😀
Re: Hotend Fan Issues
My fan is working fine, but it's far too noisy so I want to swap it for a 40mm Noctua. I already printed an adapter, any suggestions before I begin the project ?