The need for fabricating a prototype circuit arises frequently in electronics, including education and research laboratories. In resource-poor countries in the developing world, this is hindered by the high cost of commercial Printed Circuit Board (PCB) prototyping machines and long turn-around commercial fabrication process. Practical, hands-on laboratory teaching and experimentation is necessary to improve learning in electronics. In this paper, a low-cost build-your-own (BYO) semi-automated three-axis PCB milling machine for double-sided PCB prototyping is developed using commercial components and open source hardware and free open source software, to provide students, teachers, and engineers an accessible and affordable resource for PCB prototyping. Also, the main problems encountered during fabrication of PCB have been mentioned and the techniques used to solve them are discussed in detail.