Sturdy structure with frame thickness of 1-1/4 inches? Accurately adjust the vertical height of the mandrel?
Use a hand drill with 1/2'' linker for operation, drill requires M12 or M15 linker? Heavy 1/4'' thick steel frame suitable for all CNC machining? 2-axis adjustable pipe clamp, which can offset the notch by 1/2'' vertical and 1'' polished stainless steel shaft? Easy to install: use bolts to fix or fix it on the workbench, or simply fix it on the workbench, use a vise to clamp it in the vise?
Use a cheap bimetal hole saw? Requires ordinary 1/2 inch hand drill Package included: 1 Pipe & Tube Notcher.