Open-source designs are being increasingly used to develop robot hardware. When motor actuators were used for robot development in the past, it was difficult to find cost-effective commercial products. Open-source motor controllers, recently developed with the collaboration of many people, have exhibited phenomenal growth as their performance is now comparable to those of commercial products and their price is cheaper. In this study, we utilized an open-source Vedder electronic speed controller (VESC), originally developed for electric skateboards, as a general-purpose motor controller for robot control. The high-speed, high-torque, and high-output VESC was hardware-upgraded to enable more accurate current control, and advanced position and speed control algorithms were developed to produce Myongji-VESC (MJ-VESC), a general-purpose motor controller for multiaxis robot systems. To evaluate its current, speed, and position control performances, MJ-VESC was applied to an open-source planetary geared actuator that can be fabricated with a 3D printer. Based on this, we propose an open-source motor controller framework that can be universally used for multiaxis robot systems.