spice grinder 3d model

A precise mechanical design prompt for a 3D-printable vertical multi-stage spice grinder, optimized for Bambu Lab A1 Mini (max height 175-180mm, outer diameter 55-60mm for an ergonomic handgrip). The structure consists of a single monolithic main vertical cylindrical body with an integrated central rotating shaft and a top twist handle. Inside, multiple consecutive crushing stages are stacked vertically, featuring alternating fixed teeth on the outer wall and rotating teeth on the shaft, with gravity-feed funnel holes between stages. Two separate modular containers attach via screw threads: a top hopper for whole unground spices, and a bottom container for extra-fine powder collection. Crucial mechanical constraint: all screw threads must be counter-threaded (reverse-threaded) relative to the handle's rotation direction to prevent accidental unscrewing during grinding. Designed for PETG 3D printing tolerances.