SLA prototypes as well as SLS prototypes are ideal candidates to use as master patterns when casting metal parts in foundries. However, both have their advantages and it is important to understand them in order to properly choose the correct process for each application.
SLA master patterns also referred to as Quickcast prototypes are thin walled parts (.015″) with a honeycomb structure inside to add strength and integrity. Prototype castings with small features and details as well as large Quickcast parts work well for this process. They typically require a flash firing oven to burnout properly. Axis Prototypes uses a resin that has an extremely low ash residue and antimony after burnout.
SLS master patterns are essentially polystyrene based 3D printed parts that are infiltrated with foundry wax post build. These wax infiltrated parts have a sand like texture and are a good choice when a perfect surface finish is not required. Parts with complex internal channels are also ideal candidates because unlike SLA master patterns which have supports that may be impossible to remove, the SLS foundry pattern uses unsintered powder for support during the build which can then easily be blown out with air. These wax parts can be melted out of the slurry cast at low temperatures and leave virtually no residue. There is also no chance of slurry infiltrating the part like it can in a SLA part because the SLS part is solid.