Extruder skipping steps after a while
I assembled my core one this week. It runs well for a while, a few test print came out ok (a bit of ghosting I fixed later). And now, the extruder is skipping steps, it starts with a few and then almost completely fails. I disassembled it and built again to no avail. Tried everything in the book and run out of ideas.
To be clear, it can print for a while, and then suddenly start having issues. While manually moving the extruder (via LCD) I had no issues. The hotend doesn't seems to be clogged, as it starts to print ok (I used one of those nozzle needles just in case too), fans work fine too,...
There isn't many retractions in this example, so I'm out of ideas on how to fix it.
RE: Extruder skipping steps after a while
too much friction in the bowden tube?
RE: Extruder skipping steps after a while
There isn't any hard corners/curves on the bowden tube. It doesn't happen at the same height and the gcode is the same as previous prints that completed without issues, black filament is the one provided by prusa (just in case), standard settings.
The heatsink fan is working, I thought maybe there's some issue there and heat transfer up in the tube, but doesn't seems to be the issue.
No apparent clog, re-lubricated the gears, re-calibrated everything,... going crazy
RE: Extruder skipping steps after a while
Go into the user interface settings - > footer and set the free slot to heatbreak.
With the door closed, intake open and chamber fans running at 40%, I got some skipping on the first layer, when using my 0.25 nozzle with "Hilbert Curve" Infill.
The heatbreak temperature went up to 39°C and the backpressure from the nozzle was too much for the softened filament.
I then opened the door during the first layer, so the heatbreak fan could get as much fresh air in as possible.
No more skipping.
I'm not saying that it's the same issue for you, but it's a quick and good check to look at the heatbreak temp, while the skipping happens.
RE:
You might be right...
Good prints happened yesterday night (which is cooler)
Bad prints started this morning (hotter)
I started to get good results again when I remove the lid (it was easier to dissassemble and tinker with the extruder and since it's PLA ...)
It's pretty hot here (30° outside). I got a couple of skips when doing what you recommended and the heatbreal temp was 39°.
Opened door, enable chamber fans and temp deop to 35° no more issues for the moment.
I lowered the speed and will reduce the retractions for next prints. It's a lot noisier with the fans and door opened. Time to look for some Noctua to replace them, it's a start.
Thank you
RE: Extruder skipping steps after a while
30°C ambient is pretty hot, if PLA at high print speeds needs to stay around 35°C in the heatbreak.
You could try to use some "cool plate" for PLA. The Bambu print plates are compatible with the Core One, so there's quite a selection... Biqu Frostbite, Bambu Supertack, Gecko etc.
Warping might become an issue, when not heating the print sheet at all, but maybe a cool plate at 40°C might work well.
Instead of lowering the speeds, you could try to lower the maximum feedrate of the extruder (probably only visible in Export Mode). That would reduce the speeds automatically according to the extruder speed instead of slowing down everything.
RE: Extruder skipping steps after a while
Ok, has been reading a little bit and my problem was "heat creep" (English is not my first language and I didn't know the term). Thanks for the tip about the "cold" plates, I guess the compatible one is for X1, right? I think it's a bit longer than prusa's
I came from a P3 steel (open) I used to have 40º bed for PLA, surprised for the 60ºC default setting for the core one, but I never had an issue with high build plate temp since it was an open printer...
I also saw that maybe Noctua fans aren't the best either, looking for something quiet or maybe some mod to increase the airflow / reduce chamber temp. I live in the south of spain, so it's quite hot here in summer 🙁
Thank you so much for the help!! You were spot on!