This CNC milling machine that costs less than $100 (currently $87) to build. It can mill PCBs, wood, and even mild steel. All of the machine’s structure is MDO and is designed to be milled on the ShopBot. The leadscrews and leadscrew nuts require drilling and tapping operations that are preferrably perfomed on a lathe. The stepper motor drive board must be assembled and integrated with the control software. The remainder of the assembly tasks are designed to be completed with hand tools.