3D CAD Design: Snap/Press-Fit Connector for Adhesive Bra Product

I'm launching Adhesive Bra System - a fashion-forward adhesive bra with a decorative, adjustable rhinestone connector in the center. The connector is a visible jewelry-like element that provides variable cleavage control (2.5" to 5.5" adjustable width). I need a mechanical engineer/CAD designer to design the connector mechanism and deliver CAD files + a functional 3D-printed prototype. Critical engineering constraint: The connector must accommodate the existing grommet openings on the adhesive cups (0.5-0.6" diameter). Technical Specifications Attached. ****Using existing adhesive bra cups (no custom design needed) Size: 36C (MVP) Material: Medical-grade silicone Cup width: 5.0 inches Cup height: 5.5 inches Weight per cup: ~1 ounce Grommet openings: 3 brass eyelets per cup Grommet diameter: 0.5 - 0.6 inches Grommet spacing: 2.5 inches (center-to-center) Attachment points: Snap posts positioned BELOW grommet level Connector Specifications (THE ENGINEERING CHALLENGE) Width Adjustability: Minimum width: 2.5 inches (intimate/subtle cleavage) Maximum width: 5.5 inches (full separation/maximum cleavage) Adjustment type: Elastic-based mechanism (user pulls/compresses, no tools required) Adjustment should be: Smooth, continuous (not fixed increments), intuitive to use Materials: Base: Medical-grade elastic cord Decorative elements: 6-10 rhinestones (4-6mm diameter, faceted clear stones) Attachment hardware: Stainless steel snap (female sockets on connector ends) Total weight: Under 0.5 ounces All materials: Hypoallergenic, dermatologist-tested Snap Hardware Specifications Male stud diameter: 2.5mm (located on adhesive cups) Engagement depth: 0.47 inches Engagement force: Should require 2-3 lbs pressure to click, but hold securely during wear Placement: One snap post per cup, positioned below grommet level (critical constraint) Material: Medical-grade stainless steel Durability: Must support 25+ on/off cycles without degradation CRITICAL CONSTRAINT: Grommet Compatibility This is the engineering challenge you need to solve: The connector assembly must fit through OR attach below the grommet openings (0.5-0.6" diameter). The connector cannot obstruct or stress the grommet openings. The design must work seamlessly with the existing grommet placement on the cups. Deliverables Milestone 1 (Week 1): Concept + First STL Budget: $150 Deliver: Initial CAD design showing adjustable connector mechanism Two position demonstrations: minimum width (2.5") and maximum width (5.5") First STL file for 3D printing review Grommet constraint solution sketch/explanation Your recommendation for rhinestone attachment method Question: Does elastic cord approach work, or alternative mechanism? Milestone 2 (Week 2-3): Final CAD + Prototype + Technical Drawings Budget: $150 Deliver: Final CAD files (SolidWorks or Fusion 360 format + STL export) Complete technical drawings with GD&T tolerancing Assembly and stringing instructions (how to attach rhinestones) One functional 3D-printed prototype including: Elastic mechanism tested across full 2.5"-5.5" width range Rhinestones securely strung and tested for durability Snap attachment verified with actual adhesive cups (I'll send samples) Full engagement/release cycle tested 5+ times without failure All materials are production-ready Manufacturing handoff documentation Cost analysis for production scaling Budget & Timeline Total: $300 fixed price (two $150 milestones) Week 1: Milestone 1 delivery (concept + STL) Week 2-3: Milestone 2 delivery (final CAD + prototype) Payment: Split milestone payments via Upwork escrow Ideal Candidate Must Have: ✓ Mechanical engineering background (not just 3D modeling) ✓ Proficiency in CAD: SolidWorks, Fusion 360, or equivalent ✓ Snap-fit mechanism design experience ✓ 3D printing knowledge (what prints well in resin) ✓ Problem-solving skills for constraint-based design ✓ Portfolio with jewelry, accessories, or fashion hardware Nice to Have: ✓ Experience designing for elastic/flexible materials ✓ Fashion/lingerie product development background ✓ Understanding of tolerance stacking for small components ✓ Manufacturing for production scaling experience Why This Project Matters Novel product: First decorative connector system for adhesive bras (no direct competitors) Real market: Adhesive bra market is $800M+ globally; connector adds luxury positioning Scalable: After MVP validation, we expand to multiple sizes and connector styles Your engineering is visible: This connector is the hero feature customers see and feel Growth path: If successful, ongoing work for design iterations and product expansion Critical Questions (Answer in Your Proposal) Grommet constraint: How would you approach fitting the connector mechanism through/below the 0.5-0.6" grommet openings? Elastic mechanism, sliding attachment, or alternative? Rhinestone attachment: Can you design the connector to permanently secure 6-10 rhinestones (4-6mm) to elastic cord without them coming loose during 25+ wear cycles? Adjustability mechanism: Is elastic cord the right choice for continuous 2.5"-5.5" adjustment? What tensioning ensures it holds position but remains user-friendly? Prototype testing: Are you comfortable testing the mechanism with actual adhesive cups (I'll provide them)? Can you validate the snap engagement works perfectly? Material recommendations: What's your suggestion for: Resin type for 3D printing the connector body? Elastic cord material/durability? Rhinestone attachment method (glue? threading?)? What You'll Receive Upon contract start: Physical adhesive cup samples (to test your design against real product) Sample rhinestones and elastic material options Detailed technical specification PDF Product mockup photos showing current functionality Clear feedback process for iterations Communication & Expectations Response time: Answer technical questions within 24 hours Iteration willingness: Be open to 1-2 rounds of design refinement based on testing Transparency: Let me know immediately if any specs are unfeasible; suggest alternatives Quality: Designs must be production-ready, not just "good enough for prototype" Next Steps Apply with your Upwork profile In your proposal: Share your portfolio (focus on jewelry/accessories/fastening systems) Answer the 5 critical questions above Explain your approach to the grommet constraint Upon selection: Contract goes live immediately I send you physical samples + materials You start Milestone 1 design work Week 1 delivery: First STL + concept for review Week 2-3 delivery: Final prototype + all files Budget Breakdown (For Context) Your $300 covers: 12-18 hours of CAD design/engineering ($150) 3D printing materials & equipment time ($50-75) Prototype assembly & testing ($50-75) Shipping samples back to client ($15-25) Job Type: Fixed Price Budget: $300 Timeline: 2-3 weeks Experience Level: Intermediate-Expert (Mechanical Engineering)