Mechanical Product Design Engineer – Sustainable Metal Lip Balm Tube (Twist Mechanism)

Hi, I'm developing an eco-friendly, refillable lip balm tube made from aluminium (or similar alloy), designed for direct lip application rather than finger application. It uses a twist/screw mechanism, like how a standard plastic lip balm tube raises and lowers the balm, but I am hoping to manufacture it using metal. I need a designer/mechanical engineer to take this concept from sketch to a proper, manufacturing-ready technical drawing package that I can send directly to a factory for tooling and production. This is not a rendering job, I need real mechanical design work e.g. correct tolerances, thread/mechanism engineering, and material specification, so the part actually works and can be manufactured reliably. Product Requirements: Material - Aluminium (or lightweight alloy) chosen specifically for recyclability, replacing typical plastic twist-tube mechanisms. Open to your recommendation on grade/finish if it improves manufacturability or cost. Dimensions approx. 90mm length, 20–22mm diameter. Mechanism - Twist/screw-driven elevator mechanism (raises and lowers balm), NOT a push-up mechanism. Needs to be smooth, durable, and resistant to jamming or stripping over repeated use. Refillable - Tube must be designed to be refilled. My intent is that refills are sold separately, likely as a pre-filled insert (e.g. a small paper/cardboard or biodegradable cup filled with balm) that fits into the tube and sits on the twist-up platform. Open to alternative approaches. I'd like your recommendation on what's most reliable and manufacturable, including how the refill locates/grips securely so it doesn't rattle loose or shift during use. Durability - Should be/feel noticeably hardy/robust End goal: Fully recyclable packaging (aluminium body/mechanism, ideally minimal or no mixed-material components that would complicate recycling). Deliverables: - Quick concept sketch/options for the refill approach (before committing to final direction) - Full 3D CAD model of the final design - Manufacturing-ready 2D technical drawings with dimensions and tolerances, clear enough for a factory to quote and produce directly - Material and finish specification - Brief notes on recommended manufacturing method and any DFM considerations I should be aware of Ideal Candidate: - Experience with mechanical/product design for manufacturing (not just visual/industrial design renders) - Prior work on cosmetic packaging, metal tube/canister products, or small precision mechanisms (threads, twist mechanisms, spring-loaded parts) strongly preferred - Comfortable explaining trade-offs (e.g. cost vs. durability vs. manufacturability) so I can make informed decisions - Please share a sample of a dimensioned/toleranced technical drawing (not just a render) from past work Process & Communication: I expect this to involve some back-and-forth, so I'm happy to jump on calls or exchange messages to troubleshoot the mechanism design together. Turnaround doesn't need to be rushed. I'd rather get it right than get it fast. Milestone-based payment is fine (e.g. concept approval → CAD approval → final drawings). Budget: Fixed price preferred. Budget approx $600AUD for a complete, manufacturing-ready drawing, paid in milestones (e.g. concept approval → CAD approval → final drawings). Happy to hear your estimate if your process differs. To apply, please include: - A relevant portfolio sample (ideally a metal or mechanical component with a real technical drawing) - Your initial thoughts on how you'd approach the all metal screw mechanism and the refill insert/cartridge design. - Estimated timeline and how you'd structure milestones/payments Thank you!