This paper shows the results of studying the technology of manufacturing cortical electrode-instruments (EI) with the use of indirect

methods of the Rapid Prototyping technology. Functional EI prototypes were made by layered synthesis of the photopolymer material with

the use of the stereolithography technology (SLA - Stereo Lithography Apparatus). The article is focused on two methods of indirect EI

manufacturing. One of the EI prototypes was used for making a molded wax model for hot investment casting, followed by applying

copper coating. The second prototype was used for applying copper plating to a prepared current-conductive layer. As a result of EDMing

a steel workpiece, both EIs reached the desired depth, which is 1 mm. The copper plating applied to the EI preserves its integrity. Through

the use of the casting technology, there is a possibility to cut the economic costs by 35%. Using a prototype with preliminarily applied

conductive coating makes it possible to make geometrically-complex EIs.

The method of determining the accuracy of polymer molds in plaster forms has been discussed. Distortion of the surface of molds and

plaster molds has been assessed. It has been found that the presence of monolithic and porous structure in the samples does not change the

accuracy of the surfaces when forms are prepared for removing the material of the model. It has been found that in case of full-mold

casting it is more expedient to form the mold cavity with cellular adjustable structures of molding prototypes.