Moulds: How to Use AI to Design Functional Products
A practical workflow from idea to printable model, and the next step toward injection moulding.
What AI is great at (and what it is not)
Strengths
AI is especially useful when you need momentum:
Idea generation at speed: rapid brainstorming with ChatGPT or any LLM.
Fast visual exploration: creating believable “product renders” without doing hours of CAD.
Style and form studies: seeing options you might not have drawn yourself.
Early decision making: choosing a direction before investing time in engineering.
Limitations
AI will happily produce things that look right but do not work:
Hidden geometry issues: thin walls, impossible overhangs, enclosed voids, non manifold meshes.
No built-in understanding of injection moulding rules: draft angles, split lines, undercuts, uniform wall thickness.
Dimension uncertainty: AI outputs do not start with a true scale unless you impose it later.
Mesh heaviness: models can be too dense for CAD workflows, especially if you want editable solids.
Opportunities
When you accept the limits and build a process around them, AI becomes powerful:
Faster product iteration: more attempts, more learning, less CAD grind early on.
Lower barrier for beginners: you can prototype functional ideas without being a Fusion wizard from day one.
Closed loop recycling: prototype with scrap, test, refine, then move to production methods like a Desktop Injection Molding Machine.
Turning waste into value: you can literally Recycle Old 3D prints into a new product by shredding, re filamenting, and printing prototypes.
Remember, Sustainable Design Studio can help you design your product even if you don’t have concept sketches.
The workflow: from idea to printable prototype
Step 1: Brainstorm product ideas with ChatGPT
Start with constraints. If you do not tell an LLM what matters, it will prioritise novelty over function.
Here is a prompt you can copy and tweak:
Example Prompt (ChatGPT or any LLM)
“Act as an industrial designer and mechanical engineer. Brainstorm 5 functional product ideas that can be made from recycled plastic and suit small scale manufacturing. Requirements: fits within a 100 mm cube, can be 3D printed first, and later adapted for Desktop Injection Moulding using a Desktop Injection Molding Machine. Avoid undercuts where possible.”
Step 2: Create a clean product render with Gemini Nanobanana
Once you have an idea, generate a clear render in Gemini Nano Banana.
The main tip: ask for a clean background and a simple view angle. A white or light grey background makes the next step much easier, because the image is being used as a source for 2D Image to 3D Model conversion.
Ask for:
Clean background
Simple, manufacturable geometry
A clear 3 quarter view or front view
Minimal surface noise and minimal tiny details
At this stage you are not producing engineering drawings. You are producing a strong visual “seed” for modelling.
Step 3: Convert the render into a 3D model using Meshy.ai
Upload the selected render to Meshy.ai and run the 2D Image to 3D Model process.
This output is a mesh, so treat it as a prototype starting point. The goal is to get a shape you can hold and test, not a perfect CAD model.
Step 4: Print immediately, or rebuild properly in CAD
Now you choose your route depending on what you need to learn.
Option A: Export STL and print straight away
Export the Meshy STL and print it as fast as possible. This is the quickest path to a real prototype.
If you want the loop to be truly circular, you can print in Recycled Plastic. For example, you can create PET filament using our Filament Maker, then print your test parts.
This route is fast, but edits can be frustrating because you are working with a mesh.
Option B: Export into Fusion 360 and convert it into a usable model
If you plan to move toward moulding, CAD is where the product becomes “real”.
A key limitation here is mesh density. Fusion 360 needs meshes that are relatively lightweight to stay responsive. As a rule, aim for less than 10,000 triangles.
Meshy includes a remesh option, so before exporting:
Remesh down to around 10k polygons
Export a lighter STL
Use the mesh as a reference and rebuild clean geometry as solids in Fusion 360
This gives you a model you can actually engineer.
Related Resources.
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3D Printing vs Injection Moulding
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A guide on how to 3D print a SLA mould, including what you need to purchase, and the full process of doing it yourself.
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Good Product Design
A comprehensive guide to what makes a good, and bad recycled product.
