Guide3D printing or injection moulding: when does each really pay off.

With moulding you pay a lot upfront for the mould and little per part. With 3D printing there is no mould, but each part costs more and takes more machine time.

• Prototypes and versions to test and change
• One-offs and spare parts
• Small and medium runs
• Complex geometries, internal cavities, parts personalised one by one
• When the design may still change: editing a file costs nothing like changing a mould

• Thousands or tens of thousands of identical parts
• Simple geometries and a final design
• When you need the lowest possible cost per part

An injection mould is a significant investment that only pays back on large quantities.

Compare the total cost of the two routes for the quantity you really need: mould plus parts on one side, parts only on the other. Lead times matter too, since a mould takes weeks, and so does the risk of having to change the design later.

Often the best choice comes in two steps: 3D printing for prototypes and the first run, to test the product on the market, then real production. And that production doesn't always have to be moulding: with series production by 3D printing large volumes are possible too, when it pays off, with no moulds and parts printed only when needed. For some shapes, CNC milling is also worth considering.