Key facts
- Keep the idea confidential until you have taken advice on protection
- The UK IPO warns that disclosing an invention before filing can stop you getting a patent
- Use non-disclosure agreements when sharing designs with suppliers
- A 3D CAD model is the bridge between a sketch and a manufacturer
- 3D printed prototypes are a low-cost way to test form and fit
- Manufacturers quote from STEP files plus dimensioned drawings
Step 1: Protect and check the idea
Before telling the world, think about protection. A patent protects how an invention works, but the UK Intellectual Property Office warns that making your invention public before you apply can stop you getting one, so keep it confidential until you have taken advice. A registered design protects how a product looks. Talk to a patent attorney if the idea is technical and valuable.
At the same time, search what already exists: online shops, crowdfunding sites and patent databases. Finding a similar product early is not always bad news; it shows there is a market and helps you see what to do differently.
When you share details with designers or manufacturers, ask them to sign a non-disclosure agreement (NDA) first.
Step 2: From sketch to CAD model
Manufacturers cannot quote from a description or a rough drawing. They need a precise 3D model. A CAD designer takes your sketches, photos, measurements and notes and builds a 3D CAD model with real dimensions. This is where vague ideas become decisions: wall thicknesses, how parts fit together, where screws or clips go, what material it might be.
The more you can give at this stage, the less it costs: dimensions, any off-the-shelf parts it must fit (such as a battery or phone), and how it will be used and cleaned.
Step 3: Prototype and test
- Looks-like prototypes show size, shape and appearance. Photo-realistic renders do this on screen, useful for early feedback, investor decks and crowdfunding pages.
- Works-like prototypes test function: fit, strength, mechanisms. 3D printing is the usual first step because it is quick and low cost per part. See design for 3D printing.
- Pre-production prototypes are made in or close to the final material and process.
Expect several rounds. Each round of testing usually leads to CAD changes, which is why hourly billing with an agreed estimate suits this stage.
Test with real users, not just friends and family. Watch how people pick the product up, open it and clean it, and note where they hesitate. Problems found with a printed prototype cost a few hours of CAD time to fix; the same problems found after tooling is made cost far more.
Step 4: Design for manufacture
A part that 3D prints perfectly might be impossible or expensive to mass produce. Each process has rules. Injection-moulded plastic needs even wall thickness and draft angles so it releases from the mould. Sheet metal needs bend radii and relief cuts. Machined parts are cheaper with fewer set-ups and standard tool sizes. Refining the model for the chosen process before tooling is made is far cheaper than changing a steel mould later. A manufacturer will often suggest changes once they see the model.
This is also the time to think about cost per unit. Fewer separate parts, standard screws, snap fits instead of fasteners, and avoiding tight tolerances where they are not needed all bring the price down. Small decisions in CAD can make a large difference across a production run of thousands.
Step 5: Quotes, tooling and production
Send manufacturers a STEP file for each part, dimensioned PDF drawings with tolerances and materials, the quantities you want, and any finish or colour requirements. Our guide to STEP vs STL vs DWG explains the files. For moulded products, expect separate quotes for tooling (a one-off cost) and unit price. Ask for samples before approving a full run, and check them against your drawings, not just by eye.
Do not forget packaging, product labels, barcodes, any safety markings your product category requires, and product photography for selling online.
When to call dijitul
dijitul helps inventors and small businesses turn ideas into manufacturable designs: product design, 3D CAD models, technical drawings and renders at £45 an hour + VAT, then packaging and launch graphics. We work remotely from Mansfield and have supported UK businesses since 2006. If you need an NDA in place before sharing details, tell us when you first get in touch. Request a quote.
Frequently asked questions
How do I turn my product idea into a design?
Gather sketches, photos of similar products, key dimensions and notes on how it should work, then have a CAD designer build a 3D model. dijitul creates product CAD models at £45 an hour + VAT; if you need an NDA first, say so when you get in touch.
Should I patent my idea before showing anyone?
Take advice before disclosing it publicly. The UK IPO warns that making an invention public before filing can stop you getting a patent. Share details only under a non-disclosure agreement, and speak to a patent attorney if the idea is technical and valuable.
How much does it cost to design a product?
It depends on complexity and how many prototype rounds are needed. dijitul charges £45 an hour + VAT for product CAD work, with fixed quotes for clearly defined stages, such as turning a dimensioned sketch into a first 3D model.
What do manufacturers need to quote?
A STEP file of each part, dimensioned PDF drawings with tolerances, material and finish, the quantities you want, and any colour or packaging requirements. Without these, quotes will be vague or the manufacturer may decline to quote.
Can I 3D print my prototype?
Usually yes. 3D printing is a quick, low-cost way to test size, fit and basic function. Final products made by injection moulding or machining may need design changes, so treat 3D prints as an early stage, not the finished article.
Do you find manufacturers for me?
dijitul focuses on the design side: CAD models, drawings, renders, packaging and photography. We supply files in the formats manufacturers expect so you can get comparable quotes from UK or overseas suppliers of your choice.
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