Help, upper layers fail
I use the same gcode I was previously printing with success, PLA is from the same roll as previously.
This is third try with the same issue. Raft always prints fine, but up to certain layer, this mess starts.
Raft side
Any ideas what might be wrong?
Janis
Re: Help, upper layers fail
Cooling not working?
Re: Help, upper layers fail
It may be a shot in the dark but I had something similar happen when the file couldnt be read properly due to a degrading sd card.
Also, reload the stl file and look at the preview- I had a file with a missing line about 2/3rds of the way up creating a wig. I had to use mesh mixer and it fixed that one in particular.
Yeah, its that guy... 3D Nexus
Re: Help, upper layers fail
Have you tried printing with no raft? Which slicer are you using, can you try another one? It also looks like the layer height needs to be smaller. If you had the object go without issue before has the ambient air temp changed. The good prints had no print defects, if not then please post photos.
Re: Help, upper layers fail
Also, try to take a photo right after the filament starts bunching up so we can get more insight to the problem.
Re: Help, upper layers fail
Sorry for delay providing additional information 🙁
Right before this I swapped PLA for ABS and then back. Now, the brass hobbed pulley is grinding on the PLA filament. This is the same filament I successfully used before, also the issue is not related with moisture, as filament is stored in box with moisture extractor. When I push filament manually with force, it extrudes nicelly.
Experiment I did -
1. Cleaned the pulley groves.
2. Tightened up the extruder idler screws and raised up extrusion temperature 5 deg.
For a moment this helped, but then, when hobbed pulley groves got clogged again, extrusion flow changed and the same issue re-appeared.
Logic tells me, that this could be some kind of partial extruder clog.
Question
I'm going to dissemble the extruder as if this is full clog, but what to do next?
How to make sure that extrusion channel is clean ? How to clean it?
Could it be PFTE tube?
How to tell if extruder head is bad and needs replacing?
Answers to previous suggestions
david.b14 - I have printed this model many times successfully before. This affects all other prints. Cooling is working.
Ancientwolf - Thinks for idea, re-sliced, changed SD, issue stays.
Re: Help, upper layers fail
Janis
Firstly, try the Ultimaker "Atomic Method" to clean the extruder - use a light-coloured filament so you can see if any black burned filament is pulled out.
If it is, clean another 2 or 3 times. If you still get black bits out, then it could well be you need to replace the PTFE tubing (which is not such a bad idea anyways...).
Secondly (and counter-intuitive), loosen the filament tension. If it's too tight, it can damage the filament during feed (especially retractions) and cause additional friction within the PTFE tubing.
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: Help, upper layers fail
Get the eSun filament cleaner. I had a clog and did the atomic method and used a drill bit but could not get rid of all the clog. After feeding in the eSun stuff the filament just oozes out on its own once the nozzle hits the filament temp.
Question: When the filament is extrude it does it go straight down or does it curl to the side or even up?