YZ 1-50

YZ 1-50 is a six-axis desktop robotic arm with 492 mm of reach, a 150 g payload and a structure designed entirely for PLA fabrication. Built around six Feetech STS3215 bus servos, its mechanical architecture responds directly to their torque limitations. The first three joints use HTD 3M belt reductions of 3:1, 6:1 and 4:1, while the lightly loaded wrist axes remain direct-driven.

Its proportions emerge from working envelope, mechanical loading and a compact desktop footprint. Primary links of 207 mm and 181 mm establish the reach while a 160 mm shoulder height maintains a compact workspace. Wrist 1, 2 and 3 share the same Ø80 module, reoriented across perpendicular axes to reduce part variation and simplify fabrication.

YZ 1-50 combines mechanical design with a computational evaluation framework developed in Rhino. The designed geometry is continuously tested through interference detection, five-degree joint sweeps, torque estimation and printability analysis. Rather than defining the form, these computational checks inform its refinement by revealing mechanical conflicts and fabrication constraints. One sweep, for example, identified interference at Wrist 2 at 95°, establishing its operational limit at 90°.

The resulting system integrates geometry, mechanics and fabrication within a single computational workflow. At full extension, the shoulder requires an estimated 4.42 N·m against 4.71 N·m available through its reduction, with the complete structure estimated at 2.14 kg across 56 PLA components.