There’s nothing wrong with saving multiple parts in a single 3D file (so-called “grouped models”) while designing. However, the difficulty starts when you want to 3D print the models.
First of all, the prices you see when you upload a 3D model, 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 selected material. However, if you order two or more copies of a model, the price per model automatically decreases for most materials, mainly because the preparation of multiple copies can be carried out more efficiently.
Please don't look at these grouped models as a chance to get around the pricing system. The handling cost will only be charged once and will include all the parts in the 3D file. Although it may seem like a good way to save a little money, there are some risks involved.
For example, because our system will only register one model, our production workers will only expect one model. This means there could be a chance that not all of your models would be shipped at the same time.
Luckily for polyamide (MJF), polyamide (SLS), alumide, polypropylene and rubber-like (MJF) we have created specific design rules that make it possible to have several individual parts within a single 3D file.
When we establish that grouped models have been ordered in any other material, the order is canceled and you are contacted.