Case Study

3D PRINTING vs. INJECTION MOULDING

One of our customers produces a highly accurate motion sensor utilising the Earth's magnetic field. The product is used primarily in the world of sports coaching, from swimming to bob-sleighing and in orthopaedics, for recovery and prevention of muscle injuries

Whilst they build the electronics and the software, the Casing and Attachment for the unit was outsourced, being manufactured by injection moulding. The customer wanted a new style of Attachment and approached 3PS for help with the design and prototyping.

Original Attachment.



The design brief was a combination of discussion, dimensioned drawings of the original Attachment, plus a physical Interface that had to connect to the new Attachment.

The customer had received a quotation from their manufacturer (excluding design) to produce a prototype for circa £400. 3PS was able to both design the part and produce a prototype for circa £70.

Original and new Attachment.



Cleary for us it was important to get the dimensions of the cut-outs in the design accurate so that the Interface would fit cleanly to our new Attachment. Whilst we normally work within a tolerance of 100 microns we found that the Interface did not fit well to our prototype. Investigating it was found that the dimensions of the original injection moulded Attachment did not match the dimensions on the original drawing we had received.

So, with dimensional corrections an additional two iterations were required to get a perfect fit. The additional work including redesign was completed by 3PS over a period of two days.



The customer was very happy with the result and asked us to manufacture a number of units for field trials.

They then talked to us about production; they wanted 200-300 units and had been told by their manufacturer that the tooling costs for a new design would be circa £4,000. We explained to them the financial model of 3D printing and that if they wanted volumes running into thousands then injection moulding would be cheaper but for the lower volume of 300 we were able to quote circa £2,600 for the production.

We have continued designing and prototyping additional styles of attachments for them and are about to manufacture 500 units of the latest style.

With the right scenario 3D printing is extremely competitive with injection moulding, not only for prototyping where unsurprisingly it is much cheaper, but also for manufacturing.