Like the previous two prototyping methods discussed, Fused Deposition Modeling (FDM) is also an additive process. It creates the models layer by layer using a thermoplastic extrusion process.
The surface finish when using FDM is more rough than when using SLA, but the product is more robust, so it is ideal to use when functionality is more important than the visual surfaces. Parts with complex geometries are possible with FDM, and they are strong enough for functional testing. On the down side, FDM accuracy is lower than what it is for SLA.
Let us help you decide which prototyping method is best for you!