There are several instances where 3D printing a multi-bodied part is acceptable and necessary for the functionality of the part. There are other cases where multi-bodied files don’t contribute to the part’s purpose and also lead to issues after the part has been placed for production. Below is a list of types of multiple body files and whether they are acceptable to be manufactured by China Manufacturing parts.
Parts with Interlinking Components
Acceptable
These parts have features that contribute to the functionality of the part. A couple examples would be a chain, a ball bearing, or a model with a hinge. Intermoving components can be tricky to model and should be designed according to the material and technology the part will be printed in. Please refer to our Hardware Guide if you’re planning on printing parts with those types of features.
Assembly Files converted into .stl
Acceptable, but...
Assembly files converted into .stl files are sometimes processed through our China Manufacturing parts, Inc. platform, but they can lead to serious issues down the road, especially if solid bodies intersect in the assembly file. Some slicers can calculate around the colliding meshes, correct the file, and proceed with slicing. In other cases, the software can generate support material in what should be a solid wall or misinterpret which surfaces are actually on the exterior of the part. This may result in holes in your part and failed prints. Sometimes, the slicer can encounter an error that prohibits it from processing the file any further.
Although it’s not a 100% guarantee, properly mating bodies and avoiding colliding bodies in an assembly before exporting to an .stl can improve the chances of your file slicing successfully. Of course, submitting an .stl for printing that is one solid mesh is the best way to go.
Several Copies of a Body or Unique Separate Bodies
UNACCEPTABLE
Files modeled with multiple floating bodies impact calculations of print time, cleaning time and slicing effort, all of which can lead to inaccurate pricing. They also limit our partners’ ability to orient the parts to optimize for quality and surface finish. These parts will not be produced and may result in order cancellation! Instead, please upload unique bodies as their own part during order configuration.
