SV08 Stops Extruding Mid-Print

Sovol SV08
1

I have an SV08 on Mainline Klipper with a Micro-Swiss hotend and high-flow CH2 nozzle.

My last several prints, using PETG, the print gets through 10 or more layers and then stops extruding filament. The printhead continues to move on all 3 axes, but no filament comes out.

When I pause the print, sometimes I can extrude filament using the button on the KlipperScreen, sometimes I have to unload and reload the filament. Of course, all of the prints are ruined becuase the printhead continued to register that it had printed the layers.

  • The heatsink fan is running at 100%.
  • There’s no clog that has to be cleared.
  • Retraction is set to 0.5mm with retraction speed set to 30 mm/s.
  • Lowering the print speed to 20mm/s hasn’t helped.
  • For temps I’m running the extruder at 245 and the bed at 75.
  • I’ve taken the toolhead apart and cleaned the extruder, but it’s fine.

Any ideas?

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2

Hi,
Are you sure the nozzle isn’t clogged ?
With PETG, it is best to pass a cleaning filament from time to time.
And I use a bed at 80°

3

Thanks for the reply.

Yes, I’ve run a cleaning rod through the extruder, it’s not getting clogged.

I’ll raise the bed temp and see if that helps.

4

I don’t think raising the temperature of the bed a little bit changes the behavior.
The first layers will just be a little bit better glued.

5

I guess that the first thing that I would do is to check that the extruder’s stepper motor connections are firmly in the board.

The next thing that I would do is to take the section of bowden tube off and run the filament bare-nekked to the extruder. I had a cursed roll of yellow PLA that was 1.80mm in diameter and that was enough to get the extruder to skipping.

And finally, start the same print and observe if the knob on the back of the extruder motor stops spinning. That will definitely narrow things down.

Let us know what you find out please.

John

6

maybe a no-brainer, but did you check the tension of the idler gear ?

Maybe a second no-brainer, isn’t the filament on the spool tangled ?

7

I wonder if this could be a symptom of the axle backing out like was reported late last year.
Idler gear axle slips out and drops tension off the filament.

8

Thanks for the response.

I’m not sure which wires are the extruder stepper motor, so I checked them all and they’re seated tightly.

Running the filament without the Bowden tube worked, but this is an intermittent problem, so that might not be the issue.

The knob on the back of the extruder keeps turning even when the toolhead isn’t extruding.

9

Yes, I checked the tension on the gears. I’ve noticed that was an issue once before so I keep it pretty tight.

No, the filament isn’t tangled. But I have been feeding it from the filament dryer. I had a print fail this morning feeding that way so I’ve taken the filament roll out of the dryer and it’s hanging on the side of the printer now. We’ll see how this goes.

10

I’m not sure, but in the case of the axle backing out, wouldn’t I have to fix it somehow to resume printing? When the printer stops extruding I can unload/reload the filament and it goes right back to printing.

11

Thanks for all of the suggestions! I’m going to keep trying to run this down.

I found that BTT sells a module that is not only a filament out sensor but it also monitors if filament stops moving. If the filament stops feeding, it pauses the printer as if the filament were out. That would alert me to an issue and possibly save the print. I’ve ordered one of those, I’ll let you know if it’s worth the effort.

12

I installed the BTT filament sensor yesterday and I LOVE it! I only connected the filament movement sensor, but that gets me all the features - filament movement, filament out, filament tangle, and extruder issues.

Last night I started a print that has failed the previous 2 nights. TWICE the BTT sensor paused the print instead of failing it. I was able to unload/load the filament and resume the print. The filament was barely in the extruder when I unloaded, I’ll have to look into that.

I just added some code to have the printer send notifications to my devices when the sensor pauses the print and when the print is complete. The printer’s running now so I’ll have to wait until later to test it.

Since you guys suggested it, I’ve checked the extruder gear pin and twice I found that it was backed out. I printed Valerie Moore’s fix and will install it after the printer stops later.

I also purchased the BTT Eddy and will install that this afternoon.

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