Part dimensioning
according to nozzle size
The choice of the nozzle size and the geometry to be realized are interdependent. In the best case, it is recommended to design the part with the objective of producing it with a selected nozzle size.
This is particularly valid for the choice of the thickness of the walls of the part, as well as the realization of the corners.
A perfectly sharp corner is almost impossible to achieve. Changing the trajectory from one edge to the other causes an excess of material, creating a slightly thicker extrusion.
It is therefore suggested to add fillets with the same diameter as the nozzle used on the edges.
An open system will also give the possibility to adjust the profile An open system will also give the possibility to adjust the printing profile and reduce the printing speed of the outside wall to mitigate this effect.
Concerning the walls, thin walls are to be considered under a width of 2 mm.
When designing CAD models, it is advisable to adjust the wall thickness using a multiple of the nozzle outlet diameter.
For example with a nozzle of 0.4 mm it is recommended to design thin walls of: 0.8 mm of 1.2 mm, etc. so that the slicing software can correctly interpret the 3D file.
For a better mechanical resistance, it is advisable to provide a minimum thickness allowing the printing of contours and filling. Once again, a system open on the printing parameters allows to manage the number of layers used for the contour and thus to optimize the deposition strategy to integrate an adapted filling (pattern, density).
In case the size of the walls is a design imperative, Pollen AM proposes to these users to develop material output nozzles of specific size adapted to the design constraints. The extruder architecture of the Pam systems allows the use of nozzles up to 3 mm in diameter.
Synthesis of the rules for the first deposited layer
Constraint and element | Proposed solutions |
Stage of the 3D printing chain | Good practices |
---|---|---|---|
Sharp corner printing not possible | Provide for curvature equal to the diameter of the nozzle used | Modeling / 3D printing | Take into account the nozzle size of the print in the design of the edges |
Reduce the printing speed of the outer contour | Slicing | Adjust the print profile to mitigate adverse effects | |
Minimum wall thickness | The wall thickness should be at least twice the size of the nozzle | Modeling / 3D printing | Consider the nozzle size of the print in the design of the part |
Develop design-specific nozzle sizes | 3D printing | An open system offers freedom of configuration by allowing you to adapt print profiles | |
Low mechanical strength of thin walls printed in contour printing | Allow sufficient thickness to generate fill | Modeling / Slicing | Allow sufficient thickness depending on the nozzle used and work on the print profile |
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