Unique Mechanical Spinning Wristwatch Design

I am developing a custom mechanical wristwatch with a unique interactive feature:

The upper part of the watch (bezel + glass + dial) can spin manually like a spinner.

The lower case and watch hands are fixed.

Spinning is locked by default.

When the user pulls the upper part upward (lift trigger), the lock is released and the upper part can spin.

When the user pushes it back down, spinning is locked again.

This is a purely mechanical system (no motor, no spring-driven spin, no electronics).

The goal of this project is to design the mechanism, produce engineering drawings, and prepare manufacturing-ready documentation so I can prototype and mass-produce the watch in China.

Core Functional Requirements (Must-Have)
1. Locking System

Rotation is mechanically locked when the upper part is in the down position.

Lock is released only when the user pulls the upper assembly upward (axial movement).

Lock re-engages automatically when pushed back down.

Preferred concept: Pin + Slot axial locking system (or a better alternative if justified).

2. Spinning Behavior

The spinner rotates only when the user gives it manual force.

No free-spinning bearings.

Target behavior:

3–9 rotations per push depending on force

Smooth, premium, controlled inertia

Spinner slows down naturally and stops

Rotation must feel smooth and deliberate, not toy-like.

3. Movement Separation

Watch hands and movement are fixed to the lower case.

Upper spinning assembly must not affect timekeeping.

Hands must remain visible and serviceable.

4. Axial Movement

Upper part must:

Move vertically ~1–1.5 mm

Rotate only in the lifted state

Vertical movement must feel solid (no wobble, no accidental drop).

Technical Scope of Work (What the Freelancer Must Deliver)
1. Mechanical System Design

Full mechanical concept of:

Locking system

Axial lift mechanism

Rotation control (friction, inertia, materials)

Selection of:

Pivot / sleeve system

Friction control method (PTFE, Delrin, etc.)

Weight distribution for spin tuning

2. Engineering Drawings (Critical)

The freelancer must provide manufacturing-ready drawings, including:

Cross-section (section view) of the entire watch case showing:

Lower case

Upper rotating assembly

Locking pin(s)

Slot(s)

Pivot / sleeve

Friction elements

Individual part drawings with:

Dimensions (mm)

Tolerances where critical

Materials

Exploded view preferred (bonus)

Formats:

PDF for drawings

STEP / IGES for 3D files

3. Manufacturing Readiness

The design must be suitable for:

CNC machining (lathe + 3-axis milling)

Small-batch prototyping

Mass production in Chinese factories

The freelancer must:

Avoid over-complex mechanisms

Avoid unnecessary tight tolerances

Design with assembly and servicing in mind

4. Bill of Materials (BOM)

Provide a basic BOM including:

Part name

Material

Manufacturing method (CNC, off-the-shelf, etc.)

Notes for factory use

What This Project Is NOT

Not a cosmetic design project

Not a watch face or branding task

Not electronics

Not CAD-only without mechanical logic

This is mechanical system engineering.

Ideal Freelancer Profile

Mechanical engineer or product engineer

Experience with:

Precision mechanisms

Rotating assemblies

Consumer products (watches, knobs, dials, camera mechanisms)

Experience preparing designs for CNC manufacturing

Experience working with Chinese manufacturers is a big plus

Final Goal

At the end of this project, I should have:
A validated mechanical concept
Complete engineering drawings
CAD files
A package I can send directly to Chinese manufacturers for prototyping and production