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Comment on [Troubleshooting] Cannot fix a clogging issue.

rambos@lemm.ee ⁨8⁩ ⁨months⁩ ago

I believe its something simple, like heater wire losing contact or stepper driver overheating. After reading your post and even all the comments, I could ask you a lot more questions like:

Where does clog happen? Is it between the nozzle and the heat break? Did you try cold pulls and do you have a picture of filament end? How do you identify a clog? Is it just clicking noise from extruder? How do you fix a clog? By replacing nozzle? How hot is your extruder motor and stepper driver? Do you have a cooling fan on steper driver? Have you ever adjusted stepper driver vref? Did you tighten the nozzle while heated? Did you try tightening more (don’t brake it)? Is extruder fan working properly? What retraction settings do you use? Does your bowden tube have any play at both ends? Why dont you PID tune your hotend (its important especially after upgrading hotend)? Did you try printing at higher temp like 210-220C? Did you try extruding without hotend (like disconnecting bowden tube and running filament trough extruder)?

Before you answer the questions, I think you should try just extruding (low speed) at higher temp like 210C until the issue happens, then check how hot is the extruder motor and steper driver, also try pulling out the filament at (lower temp) and inapect it. Inspect the extruder and extruder gear marks on the filament. Would be nice if you report here with pictures

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papalonian@lemmy.world ⁨8⁩ ⁨months⁩ ago

Where does clog happen? Is it between the nozzle and the heat break?

It is either in between the nozzle and heat break, or in the heat break. I’ll have to experiment a few more times when I get home, but one time removing the nozzle did not fix the clog, while another time removing the nozzle did fix it.

Did you try cold pulls and do you have a picture of filament end?

Cold pulls, warm pulls, and shoving filament in until the clog clears. All clear it for a while until it eventually clogs again.

How do you identify a clog? Is it just clicking noise from extruder?

Gradual increase in frequency of ticking noise coming from extruder motor (Bowden setup) and decrease of filament extruded until eventual complete clog.

How do you fix a clog? By replacing nozzle?

See above, either pulling it out or pushing it through.

How hot is your extruder motor and stepper driver? Do you have a cooling fan on steper driver? Have you ever adjusted stepper driver vref?

I will have to check temps when I get home. There is no cooler on the extruder. I have not adjusted the Vref (had to look that up), but I originally tried tuning the stepper rotation distance before I knew there was a clogging problem.

Did you tighten the nozzle while heated? Did you try tightening more (don’t brake it)?

At this point the hot end has been disassembled, cleaned and reassembled probably close to 50 times in the last 2 weeks. It’s been done cold while disassembled, hot on the printer, after the nozzle has been torched from cleaning, you name it. Both nozzle and heat break are as tight as they can be.

Is extruder fan working properly?

Yup

What retraction settings do you use?

The printer clogs even outside of prints, so retraction is not an issue.

Does your bowden tube have any play at both ends?

Nope

Why dont you PID tune your hotend (its important especially after upgrading hotend)? Did you try printing at higher temp like 210-220C?

I had not heard of PID tuning until reading comments today. I might look into it when I get home, but as I’ve said other places I don’t think heat is an issue as reported idle temps are same as the build plate and clogs are able to be fixed by pushing filament through the heated nozzle. Also, filament still oozes from the hot end while clogged. I’ve tried printing at recommended temp, as well as far below and far above recommended, doesn’t change anything.

Did you try extruding without hotend (like disconnecting bowden tube and running filament trough extruder)?

Yes, but not enough to “test” it - what I’ll try is disconnecting the heat block, leaving the heat break attached to the printer, heat the nozzle, then try running ~1m of filament through the (cold) heat break. I’ll have to report back in a few hours when I get home.

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- rambos@lemm.ee ⁨8⁩ ⁨months⁩ ago
  I’ve read your update in OP, how did it clog in the heat break? Do you have a picture? Can you run the same test without heat break, just extrude cold filament in the air (no bowden tube). That test would show if your extruder is working properly. I still think you might have stepper driver or motor overheating. If the test doesn’t fail it would mean you should look into bowden tube/heat break
  
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  - papalonian@lemmy.world ⁨8⁩ ⁨months⁩ ago
    I repeated the test I attempted after clearing the clog (heat block detached, heat break and Bowden tube still attached) with 1000mm of filament through the cold heat break and it went fine. I’ve updated the post again; strongly suspecting heat creep. I have no idea what else I can do to try to fix it, though. I’ll try again tomorrow.
    
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- rambos@lemm.ee ⁨8⁩ ⁨months⁩ ago
  
  At this point the hot end has been disassembled, cleaned and reassembled probably close to 50 times in the last 2 weeks. It’s been done cold while disassembled, hot on the printer, after the nozzle has been torched from cleaning, you name it. Both nozzle and heat break are as tight as they can be.
  
  Its important to tighten nozzle properly. Tighten it, heat it up, tighten more, done. Both heat break and a nozzle must be clean. It’s the only way to achieve a good seal.
  
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