How to design a 3D print?
Unfortunately, not all 3D models are suitable for 3D printing. While this is completely sufficient for virtual applications (for example, if the 3D design is visually impressive), for 3D printing certain criteria must be met. This means of course that the shape and (in the case of a color 3D printing project) the color are defined, but there are also other criteria that are decisive, these also depend on the purpose and the 3D printing material. For example, in 3D printing it is also important that the orientation of the surface ("normal") is clearly defined. We have collected the most important criteria for a 3D printing project for you.
3D designs – remember to connect the edges
Two adjacent surfaces do not necessarily form a network of grid lines. For 3D models, make sure the edges are completely connected to each other so that they form a "common" network of gridlines, not two separate ones. You can easily visualize this by moving a corner - if it is a closed edge, both surfaces move, for unconnected edges, only one surface moves.
Designs for a 3D printer and closed volume (“water resistance”)
Extrude surfaces in a 3D design or combine several surfaces into one solid. This must be completely closed, i.e. there must be no holes (i.e. missing polygons).
Surface orientation is also important. For example, if a single surface in a network of grid lines ("grid") has an incorrect orientation ("normal"), this has the same effect as spacing.
In most 3D programs the inside and outside are separated by color, e.g. in Blender (depending on the settings) the outside is gray and the inside is dark blue. Check if your model is waterproof – use the “Solid Check” tool in your 3D printing toolkit.
3D printer designs – avoid diversity
Each edge can only connect two faces. Imagine you have two cubes of the same size and you move them so that they are directly from edge to edge. If the edges are separated, they are two separate bodies. However, if it is one and the same edge, the edge would connect 4 surfaces. This 3D design design would not be suitable for printing and should therefore be avoided.
3D designs – unnecessary volume
Operations such as scaling a 3D model sometimes create unnecessary volumes (called second-order shells). These are partially "useless" structures that are often free in the room and cause no visible damage. However, such structures can definitely threaten the 3D printing process. For example, if an additional structure is created in a cavity, the openings through which material is to be recovered (“escape holes”) can be closed off – which often leads to a significant increase in costs. Additionally, redundant structures may merge with other models or structures of the actual model during printing and thus render the model unusable. That's why it's best practice
3D printing designs – colliding triangles
If the triangles cross each other, this can lead to difficulties in some printing processes. While this does not usually cause any problems in the powder printing process, it can lead to complications with FDM. It is optimal to completely avoid polygon collisions in 3D printable designs. Unfortunately, collisions are common with some 3D scanning processes and if in doubt, they must be removed manually.
3D designs and overlapping triangles
If there are several triangles in the same place in a 3D model, they are said to be overlapping polygons. Particularly in the case of the SLA process, this can lead to damage because the relevant areas are exposed to multiple exposures, which is often visible in the finished 3D design and then in the finished print.
3D printing designs and special features of color printing
For full color 3D printing, in addition to the 3D printable model, we also need the appropriate color or texture information (if multicolor is required). STL files are not sufficient for this because they do not contain any color information. File formats such as . B. OBJ, 3MF or VRML convey color information and are therefore required for color 3D printing.
If you have any questions or are not sure if your model is ok, just submit it. We will be happy to advise you on what needs to be improved in your model or, if you wish, we can do it for you.
How to create templates for a 3D printer
How to make a design for a 3D printer? First of all, you need a CAD program that you can use to create the 3D printable design you want to print.
It is best to use Solid Edge or Solid Works. Alternatively, you can also use Microsoft's 3D wizard.
When creating a 3D model, you can either create a 2D drawing and then extrude it, or draw directly in 3D. It is important not to overdefine or not efully defined edges. This means that the shape should be completed in the drawing and should not have any gaps, but also that the shape should not have multiple line sweeps.
Then export the 3D model as an STL file. Now you can convert your model to G code using Slic3r software. To do this, simply import your 3D model and click "Slice with Slic3r". Some 3D printers already include software in which Slic3r is already integrated. For example, you can also slice a 3D model directly in Repetier Host. The 3D printing design is converted into G code, which is the code that tells the 3D design printer which position to move to.
