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Clicking and filament grinding out of nowhere  

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Arrakis90
(@arrakis90)
New Member
Clicking and filament grinding out of nowhere

Hello,

I've had my Mini for many months now, and the other day it started clicking and under-extruding. Here's everything I've tried so far to help the problem with no success:

1. Unload the filament and cut off the segment that was getting eaten by the extruder gear

2. Purge filament through a few times. No issue getting filament through.

3. Clean the extruder gear many times

4. Removed the idler spring bolt and scanned around inside for blockage, nothing there.

5. Removed the middle PTFE tube (from the extruder to the top of the hot end) and ensured no blockage

6. Used an acupuncture needle to clean inside the nozzle

7. Tried a brand new Prusament spool (I am only using PLA for all of this)

 

None of the above has worked so far and I'm not sure what to do next. The clicking only starts on the second layer and up while performing infill layers, it so far doesn't click when running perimeters or walls. I was about halfway through a print when this all started and the infill started to get jumbled. 

 

Here is what the issue looks like:

Bad print

Here is a video of the clicking happening during a print:

Best Answer by BogdanH:

Take hotend apart, clean nozzle & heatbreak, check PTFE tube length (replace if too short) and assemble. Finally, don't forget to do first layer calibration again.

Posted : 19/10/2021 10:52 pm
BogdanH
(@bogdanh)
Honorable Member

Take hotend apart, clean nozzle & heatbreak, check PTFE tube length (replace if too short) and assemble. Finally, don't forget to do first layer calibration again.

[Mini+] [MK3S+BEAR]...
Posted : 20/10/2021 7:21 am
Arrakis90
(@arrakis90)
New Member
Topic starter answered:
Clarifying

Does that involve performing every step here: https://help.prusa3d.com/en/guide/how-to-replace-a-heaterblock-heatbreak-mini-mini_122769/  

I've never attempted disassembly of these parts before and may not have all the parts and tools to do it on hand.

Posted : 20/10/2021 5:33 pm
BogdanH
(@bogdanh)
Honorable Member

Yes, that link describes the whole procedure. Ok, you can actually skip Step 9 & Step 14 (Heater & Thermistor), just keep in mind that Thermistor wires are very fragile.
Tools that you need are listed in Step 2 -regular tools that every 3D printer owner should have. Torque wrench isn't really needed... just use common sense to properly tighten the nozzle: it should be tighten firmly, but don't squeeze too much.

To explain my advice: if printer worked good before and you notice under-extrusion, then there can be either:
-extruder tension not set properly or is dirty inside (which you checked),
-thermistor or heater broken (you would probably notice if temperatures are wrong),
-hotend is clogged (which is usually the case).
Ok, there might be some more exotic reasons, but let's hope for the best.

Again, make sure you have PTFE tube at hand (cut to the right dimension!), because you will most probably need to replace it. Because the old PTFE tube inside heatbreak is probably the reason for your trouble -it becomes slightly shorter over the time because of high temperature.

[Mini+] [MK3S+BEAR]...
Posted : 20/10/2021 7:20 pm
Arrakis90
(@arrakis90)
New Member
Topic starter answered:
No luck

Hey Bogdan, thanks for the clarification. I just spent about an hour and a half taking apart the whole hotend assembly. I took the nozzle off, pulled out the hotend and cleaned out debris in the heatbrake. My PTFE tube was still in perfect shape and to spec. I reassembled per the guide, new thermal paste and all, but I seem to have managed to make the problem worse now however as just purging filament while loading now makes the motor click badly. I'm stuck...

Posted : 20/10/2021 9:29 pm
JSBmanD
(@jsbmand)
New Member
The same problem

Hey, I'm having the same problem now and trying to resolve it with the support. First layer is printing nice but other layers "overlapping" previous so that thing happens. If you resolve that before me can you send me the solution please? So do I.

Posted : 20/10/2021 10:34 pm
BogdanH
(@bogdanh)
Honorable Member

 

Posted by: @arrakis90

... but I seem to have managed to make the problem worse now however as just purging filament while loading now makes the motor click badly. I'm stuck...

If hotend is clean and extruder is clicking, then:
-make sure, that there's no resistance inside PTFE tube between extruder and printhead (this is rarely the case, but it happened). Maybe you disconnect PTFE tube at the extruder side and manually push the filament all the way to the heatbreak and check for obstacle.
-make sure that you don't have too much tension on extruder. Pull out the filament and set minimal tension. That is, turn the screw in just enough so tension lever stops rattling and then add a half turn -head of tension bolt should now be about flush with extruder housing.

[Mini+] [MK3S+BEAR]...
Posted : 21/10/2021 9:01 am
Arrakis90
(@arrakis90)
New Member
Topic starter answered:
Fixed

Thanks for the help @BogdanH, I was able to get my printer working again. I'm not sure which of the two solutions actually resolved the issue but I remeasured my heatbrake PTFE tube and it was 1 mm short. I swapped that out and I also performed one more cold pull while changing it out. This particular pull seemed more successful than any of my others and I was actually able to see all the way through the end of the nozzle from the top of the heat block. After recalibrating my printer actually seems to be printing even better than when I first got it!

Posted : 25/10/2021 4:51 pm
BogdanH
(@bogdanh)
Honorable Member

Very happy to hear about your success. Thank you for reporting 🙂

[Mini+] [MK3S+BEAR]...
Posted : 25/10/2021 6:48 pm
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