¶ Prime Tower
¶ Purpose of Prime Tower
Have you recall that you must have noticed such a phenomenon when loading the material. After the material was loaded and the filament extruded from the nozzle was cleaned up, the melted filament keeps oozing out of nozzle.
The oozing is mainly affected by the nozzle temperature, the inherent properties of the material, and the material's moisture content.
Purpose of prime tower - #1
As we know that for dual-extruder printers, when the primary nozzle is printing, the secondary nozzle maintains a certain temperature to save heating time when switching nozzles, and vice versa when the secondary nozzle is printing. Therefore, during printing, the filaments oozes out of the idle nozzle for more or less. If the nozzle moves to the main model for printing immediately after switching, the oozed filament will stick to the main model, badly affecting the surface quality.
Thus, the prime tower exists. That is, before the nozzle moves to the main model for printing, it first extrudes around the path of the prime tower. This can clean the oozed filament from the nozzle surface and prevent it from adhering to the main model.
Purpose of prime tower - #1
However, the purpose of the prime tower is not limited to this. Someone might ask, some machines have nozzle cleaning wipers and brushes that clean the nozzle surface after switching nozzles, which can remove the oozed material, so why is a prime tower still needed?
The reason is: when the nozzle is idle, the material pressure inside the nozzle continuously decreases as the material keeps oozing, and it may even reach a state of material shortage. If the nozzle is moved directly to the main model for printing after switching and cleaning with the wiper and brush, it may cause under-extrusion or overly thin lines in the initial distance printed. Therefore, pre-extruding on the prime tower can compensate for the pressure of the material inside the nozzle, colloquially speaking, it fills the nozzle to avoid surface quality issues such as under-extrusion or overly thin lines.
¶ Prime Tower Collapse
In some cases, the prime tower may collapse. (For example, if the prime tower is too tall, and the adhesion between the prime tower and the raft is not strong, or if it was hit by the nozzle, etc.)
Below are the considerable solutions for the collapse of prime tower:
- Re-do the leveling, make sure the printing gap is set properly.
- Choose the proper material for supports.The adhesion between different materials varies. When there is a significant difference in the adhesion between the primary and secondary materials, meanwhile a tall prime tower is required, the tower may collapse due to certain circumstances.
- Some settings in slicing software is able to be tried to increase the stability of prime tower. For example: increase the size of prime tower, increase thickness of it, change the circle tower to square tower, etc. Although, these changes increase the stability of prime tower, it may increase the printing time as well, please change them accordingly.