How to brief a manufacturer or a CAD designer

Who you are briefing

A CAD designer or product engineer turns your concept into production files: 3D CAD, drawings with tolerances, and material and finish specifications. A manufacturer makes parts or finished products from those files and quotes on them; some offer design services too. The brief is mostly the same for both. What changes is the request at the end: “design this for injection moulding” or “quote these parts at these quantities”.

What to include

Two items deserve more than a line. For dimensions, separate the critical ones (it must fit a holder, take a stock cap, hold a circuit board) from the ones where you are flexible, and let the designer propose tolerances. Tight tolerances on every dimension make parts more expensive for no benefit. For the target unit cost, work back from your intended retail price, the retailer's or platform's margin and your own, and give a range. Without one you cannot tell a good quote from a bad one, and the manufacturer cannot suggest a cheaper way to reach the same result.

Certifications depend on the product and the market: electrical products, toys, children's products and anything that touches food each have their own rules. You do not need every answer in a first brief, but naming the markets lets a manufacturer tell you what they have handled before and what testing to plan for.

What to ask for

End the brief with a precise request, so the reply answers it:

• Feedback on how the product can be made, and the likely process.
• A quote for tooling and a unit price at two or three quantities.
• Lead times for samples and for production.
• Minimum order quantities.
• Materials or finishes they would recommend instead, and why.

Common mistakes

• Sending only renders. A render shows appearance, not sizes, materials or intent.
• Leaving out quantities. A hundred units and ten thousand are different conversations, often with different processes.
• Asking for “the cheapest” without a target range.
• Putting tolerances on every dimension, or on none.
• Hiding the open questions. A manufacturer who knows what is undecided can help decide it.
• Changing the design after tooling has started. Settle the form with printed form studies first.
• Sending a different brief to each supplier, so the quotes cannot be compared.

Where a Kubikly concept helps

If you have made a concept in Product Designer, two outputs are written for this moment. The presentation page puts the render, problem, audience, size, features, materials, colourways, part list, manufacturing considerations, packaging idea and open questions on one printable page, free to print or save as a PDF. The part list downloads as a CSV with each part's role, shape, size and material, a starting point for the designer's own parts list. Each size is labelled as given or proposed, so the reader can see what you have decided. You can also export the form as GLB, OBJ or STL (STL in millimetres) as a reference model.

What they do not replace: production CAD, drawings with tolerances, material grades, finish specifications, cost estimates or certification. The manufacturing considerations on the page (likely process, wall thickness, draft angles, parting lines, assembly) are points to check, not a specification. Treat the page as the cover sheet of your brief, and add the quantities, target cost range, markets and timeline yourself.

A short template

• One sentence: what it is and who it is for.
• The problem it solves, in two sentences.
• Attached: the one-page concept, the part list, reference images, a photo of a form study.
• Critical dimensions, and the flexible ones.
• Materials or required properties, finishes and colours.
• Quantities: first order and yearly estimate.
• Target unit cost range.
• Markets, and the certifications you know about.
• Packaging.
• Timeline, and the specific question you want answered.