In FDM technology, the prime tower is crucial when creating 3D prints of multiple filaments. This tower helps in purging the extruder between filament changes, ensuring clear color changes in the final model. However, a drawback for users is the filament waste produced by the cleaning tower.
Anycubic Kobra 3 Combo or K3C, which currently supports up to 4 filaments (expanding to 8 by November-December 2024), requires a prime tower. BambuLab AMS also faces similar waste ratios.
Why waste filament in Multicolor 3D Printing?
In multi-filament or multi-color printing, a “cleaning” phase is necessary to transition between different colors or materials. This phase ensures that any remaining filament from the previous material is removed from thoroughly the extruder. This leftover material is known as the prime tower.
What Happens Without the Prime Tower?
Not utilizing a prime tower may result in incomplete clearing of the extruder during filament transitions, posing various potential issues.:
– Compromise in Print Quality: Failure to fully clean during transitions may result in undesired color blending.
– Filament Flow Problems: Incomplete clearing of old filament can block the flow of new filament, causing printing issues.
– Rise in Printing Errors: Lack of cleaning during filament transitions can lead to excess or insufficient material in specific print areas.
If there are no frequent color changes in the object, you may remove the prime tower, for example :
example of Anycubic k3c / Kobra 3 combo
Ways to Reduce Filament Waste from the Prime Tower
Let’s delve into how to minimize filament waste using certain features in slicing software.
Optimize Flush Volume in Multicolor 3D Printing
To minimize filament waste, start by adjusting the Flush Volume, which determines the material used during filament transitions. Lowering this value ( 1.0 by default, reduced to 0.4, test result was fine) can help your extruder use less material and create a smaller cleaning tower. However, be careful not to reduce it too drastically as this may impact print quality. For example, transitions between colors such as black and white may need a higher transition ratio.
Transition Within the Infill Option
An alternative intelligent approach to effectively minimize the Prime Tower is to incorporate transitions within the infill. Although this does not completely eliminate the prime tower, it prioritizes conducting transitions within the infill. This will greatly minimize the waste for models with a high infill volume. The prime tower is replaced by an unseen area of the model.
Software Settings :
Disable Prime Tower
Enable Flush into objects’ infill in Flush Options
Print Multiple Models
Printing multiple identical models in a single session is a highly innovative way to reduce filament wastage in multi-color 3D Printing. Instead of creating a standard rectangular prism like the Prime Tower, consider printing the same or different models instead. Opting for functional parts where surface color is not crucial is a smart decision when utilizing this method.
Prints by Anycubic K3C
Improve Transitions by Optimizing Model Placement
If a specific area of the model undergoes color changes while the rest remains a uniform color, adjusting the model’s position to have all transitions occur at the start of the print can minimize the size of the tower. The prime tower’s purpose is completed after reaching a certain height, similar to a regular single filament print.
Increase Layer Heights in multi-filament 3d printing
Increasing the layer height can effectively decrease the size of the prime tower, particularly for models with extensive surfaces. This adjustment can lead to more efficient results in minimizing filament waste in Multicolor 3D Printing.