Stereolithography (SLA) is generally recognised as the first and most widely used additive process for building prototypes and parts. Utilising original photopolymer materials in resin format, the SLA process builds plastic parts layer by layer to form a complete 3D object direct from 3D CAD data via a compatible format (.stl file). The Stereolithography machine processes the .stl file and builds (prints) a 3D part directly proportional to the data supplied. The process employs a solid-state laser, the beam of which traces the required shape across the surface of a vat of liquid photopolymer held in the build chamber of the machine, thereby solidifying the layer of material it touches. On completion of the first layer, the vat is lowered incrementally for the second layer to be solidified with the laser and simultaneously bonded to the first. This process continues until the part is complete. The speed at which the part is built is fully dependent on the nature of the part itself – for smaller, thin-walled models the build time will be quick, however, for larger, denser models the build time will be increased.Click here to view a video of this process in action.
The Stereolithography process often requires supports to be used during the build procedure, to accommodate and stabilise any undercuts and overhangs of the part itself. The team at Ogle adds any necessary support structures during the set up of the part and on completion of the build, the supports can be manually removed quite easily. The advantages of the SLA process include the precise accuracy of the parts built, with good repeatability and superior surface finish. The levels of accuracy achieved using this process at Ogle can meet ±0.1 mm per 100 mm. It is also possible to build relatively large parts using this process. The disadvantages of the SLA process include the necessity to post-cure parts for improved stability, which can lengthen the overall process.
Ogle has a tremendous amount of experience of building parts with the stereolithography process and can work with clients to achieve the optimum design and build parameters to maximize the best possible results. As a result the company has invested heavily in this process with a number of platforms in house.
In house stereolithography machines at Ogle:
In house stereolithography materials at Ogle: