we list tips and limits to take into account when designing a piece to be printed in 3D. You do not necessarily have to follow these rules to the letter, but taking them into account greatly improves the results of the impressions.
Thickness includes walls, roof and floor digital direct. The walls will be measured in number of perimeters, and the floor and ceiling in number of layers. A piece may have different amounts of layers on the floor and ceiling, but it will not change the number of perimeters unless the wall thickness is smaller than the number of passes. For good results it is recommended to use a thickness of at least twice the diameter of the printer's nozzle, a floor of at least two layers and a roof of at least three layers.
Engraved or embossed text
In general, when you want a recorded text or a superficial detail it is better that it is sunk in the object and not in relief. For engraved texts or sunken details on the surface, a minimum line thickness of 1 mm and a depth of 0.3 mm is recommended. For outstanding details and relief texts, a line thickness of at least 2.5 mm and a height of at least 0.5 mm are recommended.
Protrusions and slopes
The protrusions must have supports specially built to act as "scaffolding" of the piece. We can also design the piece to avoid the generation of supports turning the projections into slopes like the one in the graphic below.
To design inserts between two pieces it is important that there is sufficient distance between the parts to be joined. A snap that works perfectly in the software is not necessarily a snap that can be printed, because the software ignores the friction in the real world. Therefore, it will be necessary to leave at least 0.3 mm of play between the different parts.
Correct space between moving parts
When you want to design moving parts as links, chains or mechanisms, you have to take into account the separation between one and another surface. The space will determine the flexural capacity of the design. We recommend that a minimum space between surfaces of 0.4 mm be maintained. The more space you can afford.
Solid volume and direction of faces
To be able to use modeling in 3D printing, it must have the following characteristics:
* To be a single volume. All parts must be linked together
* Be closed. It should not have edges or naked faces
* Be correctly oriented. All faces with normal faces in the same direction and facing outward from the volume.