Rapid prototyping parts in the casting
The widely applied 3D printing technology enables the production of prototypes and serial parts. We convert CAD data records into wax plot parts or stereolithograph models at the customer's request but we are also happy to cast parts you have manufactured yourself or purchased from service providers.
For this reason, parts from a wide variety of systems are used both in direct casting and in our mould making. There is a wide range of different materials and surfaces, not all of which have the properties required for a good result.
In general, wax is always the preferred medium for the direct casting of a rapid prototyping part. Before casting, the parts are invested in a kind of plaster mould and heated in an oven. Wax has the property of liquefying under heat and flowing gently out of the mould. Plastic parts have to burn and can leave ash residue or corrode the investment material during this process.
Wax plotting systems are available on the market, which are usually associated with high acquisition costs, as well as stereolithography printers, which use a laser to cure a pure plastic dip or a wax and plastic mixture at favourable conditions. If such a plastic part is added to the casting, you have to always be aware that problems may occur, depending on the material, the requested alloy and the part geometry. The casting result then cannot be fully influenced by the foundry. A closed, homogeneous and clean surface should always be achieved with wax plot parts, roughness and also imperfections on the inside can lead to bad castings.
In mould making, the prerequisite for the parts being mouldable is that there is no reaction with the silicone compound. This means that the silicone mould’s setting process is not disturbed by the model material. For example, poorly exposed and cured stereolithographs can lead to sticky spots in the silicone mould. Wax plot parts usually break when the mould is cut but this does not negatively affect the mould result. If a model is to be moulded over and over again, it is recommended that a silver or brass cast be made beforehand, followed by cleaning in between. Stereolithography may also be an alternative here.
For more information on the production of plot parts, as well everything else on 3D printing, please visit the Modellforum section.