Support Layers

The FDM prototype process required the use of support material to fill in gaps. Since the part is built layer by layer, each layer must have a solid layer of material below it, to ensure the part builds correctly. For model which have layers which are built without any other part layers directly below them, support areas are created. These support areas can be easily separated from the model after the build is complete.

Here are some typical examples of where support material is necessary:

• holes with horizontal axis
• overhanging protrusions
• undercuts
• hollow shells
• chamfered or rounded base edges
• items with bases which are not flat

For a thin-walled parts (e.g. wall thickness of .090" or .120"), a safe estimate for the amount of support material needed to make a part is 40% of the part volume. The FDM machine requires that a base layer of support material be built between the part and the foam platform. For this reason, a small amount of support material will be used on every FDM job.

The following set of pictures shows an example of support layers for creating a FDM prototype of the letter H.
The volume of support material required to make this part is about 1/3 of the volume of the part.