Method for manual casting of polymers, in particular of polyurethanes, wherein a molded part is produced, wherein production of the molded part comprises the following steps: - providing a mold with a cavity for manual casting, - preparing a liquid polymer according to a recipe, - manual casting of the liquid polymer into the cavity of the mold, - solidifying of the liquid polymer in the mold resulting in the molded part, wherein a system comprises the mold and at least one sensor (3, 4, 5, 6, 12, 13), wherein the sensor (3, 4, 5, 6, 12, 13) detects a parameter before and/or during production of the molded part, wherein the sensor (3, 4, 5, 6, 12) provides parameter data of the parameter to the system, wherein the system uses the parameter data in order to calculate the recipe, wherein the recipe is calculated before and/or during the production of the molded part, wherein the recipe comprises at least one calculated setpoint of a production parameter, wherein the system comprises an electronic device and a display, wherein the electronic device controls the display, wherein the display shows during the production of the molded part at least a part of at least one production step of the recipe calculated according to the parameter data, characterized in that the at least one sensor is preferably an identification sensor for identification of raw materials, a weight sensor providing weight data, an ambient sensor providing ambient data, a degassing sensor for detecting degassing of the liquid polymer and/or a temperature sensor at the mold for detecting the heat curing the molded part, wherein the system adapts the recipe according to the detected parameter data and shows the adapted recipe on the display during the production of the molded part such that a user may implement the adapted recipe so as to react on certain production conditions and to eliminate production errors. - providing a mold with a cavity for manual casting, - preparing a liquid polymer according to a recipe, - manual casting of the liquid polymer into the cavity of the mold, - solidifying of the liquid polymer in the mold resulting in the molded part, wherein a system comprises the mold and at least one sensor (3, 4, 5, 6, 12, 13), wherein the sensor (3, 4, 5, 6, 12, 13) detects a parameter before and/or during production of the molded part, wherein the sensor (3, 4, 5, 6, 12) provides parameter data of the parameter to the system, wherein the system uses the parameter data in order to calculate the recipe, wherein the recipe is calculated before and/or during the production of the molded part, wherein the recipe comprises at least one calculated setpoint of a production parameter, wherein the system comprises an electronic device and a display, wherein the electronic device controls the display, wherein the display shows during the production of the molded part at least a part of at least one production step of the recipe calculated according to the parameter data, characterized in that the at least one sensor is preferably an identification sensor for identification of raw materials, a weight sensor providing weight data, an ambient sensor providing ambient data, a degassing sensor for detecting degassing of the liquid polymer and/or a temperature sensor at the mold for detecting the heat curing the molded part, wherein the system adapts the recipe according to the detected parameter data and shows the adapted recipe on the display during the production of the molded part such that a user may implement the adapted recipe so as to react on certain production conditions and to eliminate production errors.