Over extrusion on layer change. What setting to adjust this.
Hello, I am working with a new filament (Spectrum ASA 275) and on layer change it extrudes a blob of filament just at the beginning of the layer change. I have searched but don't know what to search for. Using Prusa Slicer, with random seam so I end up with lots of bumps all over the surface of the model. I have watched the printer and see this occur. I don't see it with other filaments. I did a heat tower. which showed that this filament, even thought it is ASA, it requires cooling which I found with searches on the net.
Looking the last print, the blobs seem bigger depending on the amount of distance between the end of the previous layer and the next layer. Could this be a temperature issue?
Using a steel nozzle with a sock on a standard MK3s head.
RE: Over extrusion on layer change. What setting to adjust this.
A photo of the problem will cut down on guesses. But here are two of mine.
It's probably oozing during the travel move before it gets to the spot where the seam starts. Retraction is the setting that sometimes can help, but not always.
Another issue is ASA is somewhat hydroscopic: and the absorbed water makes the filament ooze worse, drying the filament before printing is strongly suggested.
RE: Over extrusion on layer change. What setting to adjust this.
ps: random seams generally, makes for ugly scarred parts. Finding a hidden location for a seam - e.g., a corner - is generally the best way to deal with them.
RE: Over extrusion on layer change. What setting to adjust this.
Hello Tim,
I do know it is a setting as I have printed different versions of the part with different print profiles and get different results with the same filament. Not sure what I am looking for. I was in a rush and didn't have a note of the different profiles I used. Did a 4+hr print with the material shortly after with no issues using a different print profile.
Filament is dry. Less than 15%RH at 22 degrees in the storage bin. Has been dried before storage. Many prints before and after have worked. This is the first material I have ever ran through a dryer in all my years of printing. In all honesty, this filament was why I purchased a dryer. It is also the first ASA that I have printed with that requires decent cooling. No cooling and it looks like it is soaked, even after 8hrs in a dryer. With my storage, I have printed 3+hrs of TPU with no issues after building a dry box. Failed without the dry box.
In most cases, I don't have much issue with Random. A little bit of playing with retraction and I don't see much. I am testing with acetone smoothing on this project and get some really nice finishes with this material. I am looking at an aligned seam on this project as there are some very unique requirements.
It is over extrusion on the layer change. I was watching it happen, head gets to the position and then put out a blob of filament before moving. Going to look at the different print profiles I have and see with one of them may be the culprit.
I guess I should just do some test prints with the different print profiles and see which one gives me the problem.
Thanks for your comments.
RE:
If the extruder gets to a location then starts extruding before it begins moving, that is the de-retraction extra length setting (or whatever the base profile is set to). Honestly, I do not know if this can be set to a negative value to reduce the extrusion, but I'd try a negative value to see if it helps.
You can also play with Seam gap distance, since perimeter seams are usually where layer changes occur.