Print defects - cause and fix
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The following part was printed in PETG, 230C, 10% cooling and the major layers (in main section) are 0.3mm thick. I am using a BMG clone direct extruder and a dragon hot end.
There are two issues - a depressed Z seam and what would appear to be underextrusions where an outside layer line doesn't seem to fully fill the area it should fill.
Normally I would think that pressure advance would be the issue with the depressed seam but we are talking really slow speed operation so that seems unlikely to be the cause. I have tried upping the extrusion factor to 1.1 with no significant change.
As far as the apparent under extrusion, I find it hard to believe that the extruder could be slipping because of the slow extrusion rate.
The 'threaded' section is 0.1 mm layer height on the left and 0.05 mm on the right.
Thoughts ? -
The following part was printed in PETG, 230C, 10% cooling and the major layers (in main section) are 0.3mm thick.
With PETG, it’s easy to achieve results like yours
You have some options:
- Try higher temperatures. Depending on the specific PETG, I sometimes need to go up to 250°C.
- Lower the maximum layer height to 0.2 mm.
- Try another PETG - sometimes, even a different color from the same manufacturer makes a difference.
- Don’t use a part cooling fan - or just in the "threaded" section.
- Print even slower - you don’t tell your print speed, but sometimes, 20 mm are not too slow.
- Show us some better prints next time - these poor samples always remind me of my own failures
Good luck!
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@jens55 Looks like it might be printed too hot to me, although my PETG experience is minimal. If the things are printed alone then the layer time will be short and heat accumulation can be an issue. Increase the fan speed or print several of the models at the same time to allow more time for cooling.
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@infiniteloop, print speed is indeed 20 mm/sec due to the low layer time (4 sec) slowdown. Pictures with nothing wrong would be bragging
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@jens55 said in Print defects - cause and fix:
Pictures with nothing wrong would be bragging
Yup! I mostly print with PETG and really love it. The problem with this is that you have to tune the settings for every single brand and sometimes even per color of the same brand. Once, I encountered a "quality" (german supplier, cheap no-name stuff) which, in the end, rendered as unprintable - don't remind me on that, I wasted weeks on this crap
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I have been able to hide the seam by randomizing it's location rather than having it lined up. I was expecting to see random divots on the outside but in the overall scheme of things, you have to know that there is a problem before you can actually (sort off) see it. I am declaring that part of my question as solved and am now working on what I believe is an extrusion issue with the horizontal lines.
