Affordable desktop CNC routers are common in education, prototyping, and makerspaces, but most lack a rotary axis, limiting fabrication of rotationally symmetric or multi-sided parts. Existing solutions often require hardware retrofits, alternative controllers, or commercial CAM software, raising cost and complexity. This work presents a software-only framework for indexed rotary machining on GRBL-based CNCs. A custom post-processor converts planar toolpaths into discrete rotary steps, executed through a browser-based interface. While not equivalent to continuous 4-axis machining, the method enables practical rotary-axis fabrication using only standard, off-the-shelf mechanics, without firmware modification. By reducing technical and financial barriers, the framework expands access to multi-axis machining in classrooms, makerspaces, and small workshops, supporting hands-on learning and rapid prototyping.

翻译：经济型桌面数控雕刻机在教育、原型制作和创客空间中已十分普及，但多数设备缺少旋转轴，限制了旋转对称或多面体零件的加工能力。现有解决方案通常需要硬件改造、更换控制器或使用商业CAM软件，从而增加了成本与复杂度。本研究提出了一种适用于基于GRBL数控系统的索引式旋转加工的纯软件框架。该框架通过定制后处理器将平面刀具路径转换为离散的旋转步进指令，并经由基于浏览器的界面执行。虽然该方法无法实现真正的连续四轴加工，但仅需使用标准现成机械结构且无需修改固件，即可实现实用的旋转轴加工功能。通过降低技术与资金门槛，该框架扩展了课堂、创客空间和小型工作坊对多轴加工的接触途径，为实践教学和快速原型制作提供了支持。