Extrusion failure(?) at around 90% finished
I have a job in which the extrusion appears to be suddenly lowered above a certain z-height. Originally, the job was two pieces and the change happened to the second object just above the height of the first object. I tried printing the second object on its own, but the same thing happened.
In looking through the various filtered views of the sliced model, the main change I can identify at that layer height is in speed, which obviously affects volumetric flow as well. I've played around with nearly all the speed and volumetric flow settings to see if I can get a different result in the slicer, to no avail. I'd like to understand why it's changing at this particular z-height and what to adjust in order to successfully print this object.
It definitely has to do with the filament definition, somehow, as I was able to successfully print the same object (using the same project file), using another PLA. But I can't sort out why it only happens above that z-height.
RE: Extrusion failure(?) at around 90% finished
can you please supply a copy of your project file for that item,
you need to save the project filem then ZIP Compress the file, and add the ZIP File to the forum,
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
RE: Extrusion failure(?) at around 90% finished
Thank you
Silly question... Are you using the filament that you think you are using? I occasionally use the wrong settings... recently I thought I was using PLA... and the ASA filament that was actually loaded, objected with under extrusion...
I don't know how this part fits into your overall model, however I wonder why you have tr9ied printing the model with the hole, horizontal...
typically the top of the hole is likely to droop a little printed this way, (that will not cause the issue that you are experiencing, but it is likely to provide less pleasing results) the layer lines will be in the same plane as whatever goes through the hole, which may lead to early failure, under stress.
If you could print the part with the hole vertical, the hole would print more accurately rounded, and the layer lines would be perpendicular to the hole, which may result in a stronger item,
additionally printing with the hole vertical may identify whether the issue that you are seeing, is a geometry related issue or a height related issue, or a time related issue...
the mini, is a bowden feed printer, when I was using my MMU1 that was also bowden feed, and I found that reducing the default retractions from 4mm to 2mm reduced under extrusion problems
could you try this on the Mini?
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
RE: Extrusion failure(?) at around 90% finished
@joantabb thank you for the thoughtful answer.
I've double-checked the filament, both on the printer and in the job, as well as having a colleague triple-check me. Can't be too careful - this is definitely something I've run into before, too.
Regarding the hole being horizontal, all I can say is...d'oh <insert facepalm noise here>. That would be the first thing I'd suggest to my students and it literally never occurred to me, looking at this job over and over.
I did try printing a different object to see what would happen. This one was hollow inside but didn't have holes through the shell. It printed further before having the problem, but about the last 10% had what looks like a similar issue with layers not being fully extruded. Not identical, because the long ends didn't have uneven extrusion, rather they look like evenly poor extrusion that didn't stick to lower layers well. I've attached that project file as well, in case this helps.
It's definitely related to the filament, as I was sucessfull in printing the original object (with the hole) with some generic PLA, using an otherwise unchanged project file. (I think it was eSun, but can't be sure; no label on the spool.) I printed it both hole horizontal (to check) and hole vertical (for the better end result, which it definitely was!). Neither had any problem, unlike the Lynx PLA filament.
We were checking the various filtered views in the sliced side of the project file and are going to play with the volumetric limits a bit to see if we can generate a different result. I'll also try changing the retractions to see if that helps.
Thanks again for all the suggestions!
RE: Extrusion failure(?) at around 90% finished
The part you shared prints OK on my Mk3.9
Good luck with your Quest.
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