Mechanical CAD Engineer Needed – Precision Hand Tool with Removable Micro-Feature Cartridge Anyone

Mechanical CAD Engineer Needed – Precision Hand Tool with Removable Micro-Feature Cartridge

Project Description

I am seeking an experienced mechanical CAD/product design engineer to develop production-ready 3D CAD for a patent-pending, non-electronic precision hand tool.

This is a static manual device with no motor, gears, springs, or moving mechanical assembly. The primary functional component is a removable and replaceable cartridge located within the tool head. The exterior head and handle/base remain stationary during use.

The cartridge contains the critical working geometry and must be modeled accurately at a small scale.

Core Product Architecture

The device consists of:

- A stationary ergonomic handle/base
- A stationary cylindrical or streamlined upper tool head
- A removable precision cartridge integrated into the working area of the head
- Multiple narrow surface channels/slits incorporated into the cartridge
- Internal upper and lower guide surfaces that keep individual hair strands aligned as the tool passes across a lace surface
- A precision micro V-bezel / V-shaped capture geometry positioned within each working channel
- A controlled micro-friction surface located at the V geometry
- Internal retention/capture geometry behind the primary contact point
- A removable cartridge design that allows the functional working surface to be replaced without replacing the entire tool

The functional concept relies primarily on passive geometry, controlled friction, dimensional clearance, and guided material movement, rather than mechanical clamping or powered components.

Critical CAD Requirement

The most important portion of this project is accurately developing the micro-scale working geometry.

The CAD engineer should be comfortable working with:

- Small precision features
- V-shaped channels or bezels
- Narrow clearances
- Micro-textured or friction-enhancing surfaces
- Thin guide walls/lips
- Functional slots and channels
- Replaceable cartridge interfaces
- Tolerance-sensitive geometry
- Injection-molded and/or precision-manufactured parts
- Design for Manufacturing (DFM)

The micro V-bezel must function as a controlled narrowing/capture area rather than as a decorative groove.

The surrounding upper and lower guide surfaces are intended to keep the hair aligned and directed toward the functional V area during use.

The cartridge must also fit securely within the stationary head while remaining removable for replacement.

What Is Already Available

I am not asking the designer to invent the mechanism from scratch.

I already have:

- The overall product concept
- Patent-pending documentation
- Reference images and diagrams
- Product dimensions
- Functional descriptions
- Visual references for the intended exterior form
- Internal mechanism references
- Cartridge concept
- Working geometry direction

The engineer's role is to translate the existing design into accurate, editable, manufacturable CAD and provide professional input where tolerances or manufacturing methods need refinement.

Exact proprietary micro-dimensions and detailed mechanism information will be supplied after NDA execution and selection of the appropriate designer.

Preferred Experience

Strong preference for someone with demonstrated experience in:

- Mechanical product design
- Precision consumer products
- Injection-molded plastic components
- Small replaceable cartridges or inserts
- DFM / Design for Manufacturing
- SolidWorks, Creo, Fusion 360, Inventor, NX, or comparable parametric CAD
- Prototype-ready CAD
- Tolerance analysis
- Small-scale functional geometry

Please provide 2–3 examples of manufactured or prototype-ready products that you personally modeled.

I am less interested in photorealistic rendering experience than in accurate mechanical CAD and manufacturable functional geometry.

Deliverables

Final deliverables should include:

- Fully editable native parametric CAD files
- STEP/STP files
- Complete assembled tool model
- Separate removable cartridge model
- Internal functional geometry
- Exploded assembly view
- Dimensioned technical drawings
- Relevant tolerances identified
- Basic DFM recommendations
- Files suitable for prototype fabrication and manufacturer review

The CAD should remain parametric wherever practical, particularly around the micro-feature geometry, so critical dimensions can be adjusted after physical prototype testing without rebuilding the entire model.

Project Structure

I prefer a fixed-price milestone project, not an open-ended hourly contract.

Suggested structure:

Milestone 1 – Exterior Form & Cartridge Architecture
Create the overall body/head and removable cartridge relationship based on supplied references.

Milestone 2 – Precision Functional Geometry
Develop the internal channels, guide surfaces, micro V-bezel, friction area, retention geometry, and cartridge interface.

Milestone 3 – Final Engineering Package
Complete revisions, DFM review, technical drawings, exploded view, native CAD, and STEP files.

Target budget for the core CAD project is approximately $450–$500 fixed price. I am willing to consider a higher proposal from an engineer whose portfolio demonstrates highly relevant precision-product and DFM experience.

Screening Question

Please answer this in your response:

Based on the project description above, what feature do you believe will require the most careful tolerance or manufacturing consideration, and how would you approach modeling it for prototyping and later production?

Generic responses or portfolios consisting primarily of architectural work, visual rendering, animation, or unrelated 3D art will not be considered.

I am specifically looking for a mechanical CAD/product engineer who understands precision functional parts. read less