English
Forums
English forum
Original Prusa i3 MK3 & MK3S & MK3S+
How do I print this? (Printing help)
Clogging extruder on certain parts
 
Notifications
Clear all

Clogging extruder on certain parts  

    Last Post
  RSS
bradley22548
 bradley22548
(@bradley22548)
New Member
Clogging extruder on certain parts

I recently started having problems with my Prusa MK3. When printing overhangs or if your to close the print bed the extruder will clog. Since adjusting the z height the only time I have a problem is when it goes around the edge and the edge of the print will lift up. How can I keep this from happening

Posted : 16/07/2018 8:35 pm
JoanTabb
 JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Clogging extruder on certain parts

Hi Jason,
could you show us a pisture of your first layer on one of the defective prints?
please?

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 19/07/2018 3:07 am
bradley22548
 bradley22548
(@bradley22548)
New Member
Topic starter answered:
Re: Clogging extruder on certain parts

I have attached some photos. i just replaced the nozzle. For some reason it just starts skipping steps. It worked great after about 5 spools of plastic. Now it does this no matter what plastic I use. The orange part is from another printer that I have.

Posted : 14/08/2018 7:29 pm
bradley22548
 bradley22548
(@bradley22548)
New Member
Topic starter answered:
Re: Clogging extruder on certain parts

I was trying some things today. As soon as it clogs up. I can get the filament out. At the end of the filament is a area in which the filament was heated and cooled really fast, making it impossible to push it back through again. I took down the retraction distance by over half and it still did it. Is it possible the ptfe tubing is bad?

Posted : 14/08/2018 7:44 pm
bradley22548
 bradley22548
(@bradley22548)
New Member
Topic starter answered:
Re: Clogging extruder on certain parts

replaced PTFE tubing. Filament was going through nicely. Then halfway through the print it did it again. I am beyond frustrated at this point. Could the stepper driver be overheating and causing some issues?

Posted : 23/08/2018 7:20 pm
mike venderdahl
 mike venderdah...
(@mike-venderdahl)
New Member
Re: Clogging extruder on certain parts

I also am having this same problem now.

Posted : 29/08/2018 3:26 am
bobstro
 bobstro
(@bobstro)
Illustrious Member
Re: Clogging extruder on certain parts

I'd suggest previewing the gcode to get an idea of what's going on. If you're using Slic3rPE, slice the part then save the gcode file (important). Use the Preview button in the Plater view. Use the slider at the right to scroll up and down within the model to the layer where failures seem to be happening.

  • Is the layer small? If so, the nozzle is going to spend a lot of time there compared to larger areas and the filament may not have sufficient time to cool. Take a look at Filament Settings->Cooling->Cooling thresholds. What is Slow down if layer print time is below set to? This setting will slow down printing to ensure each layer takes a minimal amount of time. Prusa sets it to 20, the default for Slic3r is 5. You could try reducing this value to see if slowing down helps on those layers. You can also set Min print speed although you can only go so slow.

  • Back in preview mode, set the View option at bottom left to Speed. Check the Retractions and Unretractions options. are there a lot of retractions happening at the failure point? You can try adjusting Printer Settings->Extruder 1->Retraction settings. Make sure Length is < 1mm (Prusa recommends 0.8mm). Any more and you're pulling molten filament up from the hotend into the cool zone, which can result in clogs as spongy filament is pushed back in. Look at Minimum travel after retraction. This is how far the nozzle must move before a retraction will occur. If this is too short, a lot of rapid retractions may occur. Prusa sets it to 1. Slic3r defaults to 2. You can try 5 or more to see if it helps reduce jams.

    • Generally, if a model fails at a particular point, spend some time in preview to see if there is anything specific that triggers the problem. Remember that you have to save the gcode file for some options to be viewable.

    There are a slew of posts on general heat and extrusion issues with more general hints.

    My notes and disclaimers on 3D printing

    and miscellaneous other tech projects
    He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

    Posted : 29/08/2018 6:16 am
      All forum topics
      Previous Topic
    Next Topic  
    Share: