Custom Small Watch Movement Design

The task is to engineer a fully-mechanical movement that fits a compact case while providing reliable, simple timekeeping—no chronograph, no tourbillon, just hour-and-minute indication with smooth, traditional hand-winding feel. The case interior is modest in both diameter and thickness, so every component—from main plate to balance bridge—must be optimised for a tight footprint without sacrificing accuracy or serviceability. I have not locked in material choices yet; stainless, brass, titanium or a combination are all on the table, and I welcome your guidance on machining tolerances, finishing options and long-term durability. Deliverables • 3D CAD files (STEP + native format) of the complete movement assembly • Manufacturing drawings with tolerances, exploded views and BOM • Prototype-ready files for CNC or EDM fabrication • Assembly and lubrication guide • Accuracy target: ±15 sec/day after regulating on a standard timegrapher Acceptance criteria 1. Movement must fit inside the provided small-case dimensions once I supply final measurements. 2. Winding, setting and power-reserve tests pass 48-hour continuous run. 3. All parts can be produced on conventional micro-machining equipment or reputable Swiss/Japanese suppliers. Throughout the project we will iterate via video or annotated PDFs, and I will handle prototype cutting once files are approved. If you routinely work in SolidWorks, Fusion 360, or similar, and have prior calibre design or modification experience, this should feel right in your wheelhouse.