Re: Getting started with PETG (on the Mk2.5)
That 240°C nozzle and 85°C bed could be part of your problem. The first layer nozzle needs to be as cold as possible with the bed as hot as possible.
Don't think that is an issue. One of our printers prints almost exclusively PETG at these exact temps for all layers. Not a problem.
Re: Getting started with PETG (on the Mk2.5)
Although I may have missed it, how well have you cleaned your bed? I mean, really cleaned it. Soapy water cleaned etc. There are plenty of threads out there on this topic.
Also, have you checked for a partial blockage? How old is the nozzle? Perhaps consider changing it out?
Re: Getting started with PETG (on the Mk2.5)
Cleaned like the best I could, tried even soap despite my usual isoprop tissues.
Re: Getting started with PETG (on the Mk2.5)
And, have you checked for a partial blockage? How old is the nozzle? Perhaps consider changing it out?
Re: Getting started with PETG (on the Mk2.5)
Thanks for asking further. The nozzle is kind of brand new.
During Upgrade to Mk2.5 I broke my temp sensor, so I replaced Hotend and nozzle very shortly before beginning the experiments that led to this thread;
actually I did a small print with ABS as first print with that nozzle (I do not have PLA at home) to calibrate my live Z and then went over to PETG.
How do I check for a partial blockage?
Re: Getting started with PETG (on the Mk2.5)
First way is the needle approach. Stick the acupuncture needle up the nozzle when it has reached printing temp. Do it a few times. I think there is an article about it in the PR help guides.
Re: Getting started with PETG (on the Mk2.5)
Which needle diameter do I need? I had one with my first extruder (half a year ago) but that broke at some time when I had a large blob and fixed that. For ABS I never needed the needle.
I also tried two cold pulls (PETG at 90 degrees when it cooled down form 230) – but the prints afterwards look basically the same the already in the photos. So I slowly just feel dumb and have no clues left.
Re: Getting started with PETG (on the Mk2.5)
[mod mode on]
Moved topic to the MK2.5 section.
[mod mode off]
Thomas
Re: Getting started with PETG (on the Mk2.5)
Well, the same needle I guess. They are on ebay.
Re: Getting started with PETG (on the Mk2.5)
To be honest, if it were me right now, I would go back to PLA and make sure I can get a good print using that.
To keep things as simple as possible just manually change the z offset (via the printer). Use the calibration squares and make sure your PLA looks good. Then manually change the z offset and try again with PETG.
💡 Make sure that you remove any "additional" gcode you have been using trying to fix the issue.
Re: Getting started with PETG (on the Mk2.5)
After quite some time, a preliminary powder coated PEI (not completely even) and sending the printer to repair I am just struggling with thislittle unevenness. It might have been the z-axis bearings as far as i understand the report.
I am even back to the completely default settings for PETG in slic3r, despite the first layer being printed a little slower.