Our online prices are only valid for single model files. The reason is that in addition to the printing cost, each model has its own handling cost, and this cost depends on the model as well as the material you choose. Grouped models will charge the handling cost only once as the system sees it as 1 model instead of many. It may seem like a good way to save a little money but there are some risks involved.
For example, because our system will only register 1 model, our production floor will only expect 1 model. This means there is a chance that not all of your models will be shipped. Below you find some issues related to uploading grouped models.
Ordering Copies of a Model
Intersecting Grouped Models
Grouped Models Positioned Far Away
Connected Grouped Models
Grouped Models for Polyamide and Alumide
O Part, Where Art Thou?
Combining Parts on a Ring
Another option that will allow you to have multiple shells printed in one go is to place all of your parts into a container. This means that you will need to design a container around you parts. Here are some basic things to take into account when designing that container. Always engrave your container with a unique label identical to the filename of your design so we can easily identify your box as we won’t be able to check the contents of your container. Use a clearly readable font such as Arial Black for the engraved text. We recommend using letters with a minimum line thickness of 1 mm, a depth of 0.8 mm, and an overall height of at least 3 mm.
It is advised to use a perforated container because that will allow us to remove most of the excessive powder from your parts. We recommend the following minimum feature sizes for your container: at least a 1.2 mm thickness for the grid lines; and a minimum of a 4 x 4 mm square up to a maximum of 15 x 15 mm. Make sure the parts on the inside of your container cannot pass through the perforations of the container to ensure that all your parts stay together. Parts that pass though the holes might get lost.
In addition to your container features, you also need to keep a minimum spacing distance of 3 mm between each individual part and between the sides of the container and the parts. If the distance is smaller than this, parts might get sintered together.
If the overall volume of your container is larger than 1700 cm³, you should limit the density in the container because parts that are too dense can cause an irregular cooling down process. This may cause yellowing and deformation of your parts. Limit the total volume of the model to 10% of the overall volume of the container.
If you have fragile parts in the container, we recommend connecting the individual parts to the container. This will prevent fragile parts from hitting each other during shipment. Otherwise, your parts will be loose in the closed container and may damage each other by moving around during the shipping process.
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. Because parts will be connected to each other as well as a container, this may prevent every edge and corner from getting sandblasted. 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.