In this post we’re going to cover what a 3D print support structure is, when it’s required and how they can affect the quality & price of your print.
3D printing works by depositing material layer by layer, depending on the complexity of the model this will sometimes require support material. This requirement to use support material is completely dependant on the process and in this post we’ll go through different scenarios when they’re used.
Fused Deposition Modelling (FDM) prints each layer by extruding melted filament along a pre-determined path. As the material is deposited, it cools and forms a solid layer. Each layer is slightly offset from the previous, where the model and print at a maximum offset of 45°.
However when this overhang angle of 45° is exceeded, support material is required to prevent the new layer from sagging. The support material acts as a bed, for the newly deposited layer to rest on creating the desired overhang angle.
Depending on the machine type (single, dual or material mixing) there are three different support types available these are:
This is the most commonly used support type in 3D printing as any printer can print these successfully by tuning their slicer settings.
This type of support is used for intricate parts and also parts with a lot of support. This minimises material cost and post-processing.
This type of support is best suited for any detailed prints, as it allows an offset of 0mm between the support and the part creating a smooth surface.
When applying supports to models consider the three following letters; YHT. Which letters don’t require support? What letters can be printed using bridging techniques? etc.
Stereolithography (SLA) or Digital Layer Printing (DLP) require a different type of support, not only has the part got to be able to hold it’s own weight from sinking, but the part must also support itself, resisting the suction forces when carrying out a lift manoeuvre.
These types of support structures look like thin ribs, with only small tips interfacing with the model. Typically diameters of 0.3 – 0.4 mm are recommended for SLA / DLP supports, with smaller diameters making for easier clean-up.
Part orientation is paramount in successfully printing a part. Firstly the part must be bonded well to the build surface, usually this is done on a flat face to ensure maximum adhesion. Are there any undercuts that require support? How easy are they to remove? It’s bad practice to create parts that are difficult / impossible to clean-up.