3D printer stringing and nozzle oozing are two common 3D printer problems that usually share the same root cause. Printing too hot and using inadequate retraction settings.
Signs of stringing and oozing:
The signs on stringing and oozing are usually quite obvious, as seen on the print in the image. There will be bits of filament fraying off your print and some areas of the print will have excess filament where it has oozed. You may also be able to see the filament is very runny coming out of the nozzle.
Explanation:
As filament stringing and oozing is often caused by incorrect printing temperature and retraction settings. Printing too hot will cause the filament to be too runny and also mean it will take longer to cool once printed allowing for stringing and oozing. Not having enough retraction can also mean more filament is being extruded and causes these issues.
How to fix:
Increase retraction distance
Increase the retraction distance in your slicer. There’s usually a limit for how far up you can retract filament before you’re running into other issues, but as a general rule of thumb: up to 3mm is ok for most direct extruders, 4-6mm should be ok for long Bowden systems.
Increase retraction speed
Increase the retraction speed. Maximum speed depends entirely on your extruder, so it is hard to come up with a valid recommendation, when in doubt try up to 40mm/s. Check with your printer manufacturer.
Arrange prints closer
Long travel distances around the build plate tend to make your 3D print stringy, so if you can rearrange the objects to be closer on the bed, this could help against stringing 3D printing. This may not be an option for single item prints.
Increase travel speed
Try increasing your travel speed in your slicer. Travel speed is the speed the speed the nozzle moved around the print bed. More speed means less time to ooze between layer points.
Calibrate steps and multiplier
Whenever you encounter any sort of extrusion issues, make sure your basics are covered – properly calibrated extruder steps/mm and extrusion multiplier, both are key to nice prints. Over-extrusion encourages 3D print stringing. See [Over Extrusion].
Increase cooling
Increase cooling fans. Try increase in 20% increments, or try 100% when bridging or excessive stringing occurs.
In some instances 100% fans may not be enough. Some users fit additional cooling fans or even just put a desktop fan next to your printer to increase airflow.
Print single objects
If printing multiple parts at once, try printing single objects instead of placing multiple objects on the build plate. This eliminates all travel moves between multiple objects and will cut down on 3D printing stringing & oozing between multiple prints.
Filament specific tips:
Flexible filament usually needs longer retractions as it stretches while being pulled backwards. However retractions on flexibles is even trickier than actually printing flexible filaments, so you might be forced to go with shorter or even no retraction at all in order to be able to print it in the first place.
ASA, like ABS, reacts strongly to sudden temperature changes. If you all of a sudden blast it with full part cooling fans, it might crack.