Nowadays, added value of conventional ring yams has been decreased therefore importance of core-yams has been increasing whether producers or consumers. Because of reflecting the positive side of the both component to the new yarn structure by composing two different component, in the future it is reported that these yarns can be used especially in technical field. In this study, modified conventional ring spinning machine is presented in order to produce core-spun yarns with elastane and developed a software on behalf of controlling automatically this system. By changing different production parameters of machine, core-spun yams with different elastane ratio has been produced by 100% cotton and 50/50% cotton/viscose roving. The effect of changed production parameters have been investigated by applying tensile strength (Rkm) and elongation (%) tests.