In general, we recommend a wall thickness of at least 0.8 mm. Large parts may require larger wall thicknesses or added ribs or fillets for reinforcement. It is possible to have thinner features with walls of only 0.6 mm for living hinges, but here the length needs to be limited to 10 mm when they are only attached at one end or 25 mm when attached from two sides. Although hinges can be positioned differently without the risk of breaking (thanks to the isotropic mechanical characteristics of the material), it is advisable to avoid making the thinnest sections of your living hinges parallel to the Z plane.
Please note that the Rubber-like material has a hardness of Shore A 90, which means it is a hard material on the Shore A hardness scale. To get a flexible design, it is advised to keep the walls below 5 mm. In general thinner walls will be more flexible and thicker walls will result in less flexible and harder sections.
Hollowing & Holes
We advise hollowing out a solid model as much as possible, and when the wall thickness exceeds 20 mm. We recommend a wall thickness of 1-2 mm and the inclusion of at least two holes with a minimum diameter of 10 mm for powder removal.
It is possible to create holes or perforations and ducts. The recommended minimum diameter size of these holes is 2 mm but some post-production will be needed to remove excess powder. Some residual powder may be stuck on the inside of complex ducts. It is advised to design a strip or chain through the duct to help in dislodging the powder once the part has been printed. In general, complex holes or ducts require larger diameters in order to achieve thorough removal of the unfused powder.
It is possible to print interlocking parts and assemblies in a single build. Parts that are printed together should have a minimum clearance of 0.5 mm.
Embossed and Engraved Details
For embossed or engraved textures, we advise a minimum thickness of 0.25 mm. For legible engraved or embossed text, we recommend letters with a minimum line thickness of 0.5 mm, a depth of 1 mm, and an overall height of at least 2.5 mm.
Guidelines for Grouped Models
It’s possible to have several individual shells within a single 3D file. If the shells are part of interlocking elements, such as chainmail, for example, consult the rules indicated in the “The Right Space Between Your (Moving) Parts” a paragraph earlier. If the shells in your design are not interlocking or intersecting, additional design rules and considerations can be found below.
O Part, Where Art Thou?
One way of making sure all the shells in your design stay together and can be processed as one part is to connect the different shells with support beams. It is important that the parts are well connected and that the connection beams are strong enough. Use a minimum wall thickness of 3 mm as anything thinner will not be strong enough to support the different parts of your design.
The heavier/bulkier your individual parts are, the thicker the connecting beams should be. If the connections between the parts are too weak, there is a risk that your parts might get lost. You can prevent bulkier shells by hollowing them out. Just don’t forget to provide several large drainage holes so that the powder on the inside can be removed – otherwise, your part will not become lighter. The part’s wall should be less than 5 mm thick.
It’s also advisable to have 4 firm connections per shell. The larger the shells, the more difficult they are to connect properly. That’s why the sum of the dimensions of the imaginary box (X+Y+Z) around your design should be less than 350 mm.
Combining Parts on a Ring
Once printed, each model will need to be cleaned with a brush and sandblasted to remove the excess powder stuck to your model. This is the same for grouped models but in these cases, access to all of the parts is more difficult. Please be aware that some residual powder might be present when receiving your parts. To clean your parts further, the residual powder can be removed with a brush or compressed air.
Please be aware that grouped models are only offered in natural finish. Because of the limitations stated above for these types of files, a good result cannot be guaranteed. Other finishes can be achieved through various post-processing techniques but will require perfectly cleaned and fully accessible parts, which is not possible for grouped models enclosed in a container immediately upon printing.
274 x 370 x 380 mm