The solution is injection moulding...

Injection mould tooling for low volume production parts.

Initial SLS prototypes for testing in only a few days.

prototype partsRequirement:

Having previously worked together on an additive manufacturing project, PSM were keen to get more value out of their relationship with Plunkett Associates on their next production design. Knowing that Plunkett's have a strong track record of delivering production quality parts in prototype lead times; PSM approached them with their latest idea.


In order to evaluate the technical feasibility and market prospects of their new maritime device, PSM generated a set of CAD block models. These were additively manufactured by Plunkett Associates supply base as SLS prototypes in a few days.

Following several weeks of assembly, dis-assembly, testing, review and discussions of the prototypes at PSM, Plunkett’s were asked to move the project forward so the mechanical parts were suitable for production by injection moulding and would be right first time at the tool trial (T1).

injection mould toolingPlunkett’s imported the CAD data and enhanced the design for manufacture by injection moulding. This included creating a constant wall thickness, designing out undercuts, adding location features, strengthening ribs, screw bosses, draft and fillets; in addition to maintaining the units styling, design intent and dimensional fitting conditions.

The unit consisted of 4 parts that assembled to make an enclosure for maritime electronics. 3 of the parts needed to be tough and rigid to withstand the rigours of a life at sea (on hard tack) and support the PCBs and LCD screen. In contrast the fourth part was a flexible cover that protected I/O connectors at the front of the unit and could be easily peeled off and re-attached while still providing a splash proof covering.

Prototype partsMoldflow CAE software was used to simulate the plastic flow during moulding; confirming that the parts would fill correctly and that any potential cosmetic or structural issues could be tackled by the appropriate tool design and processing.

After several days of work and the exchange of numerous images and data, PSM signed off the work for a series of low volume polyurethane prototypes. Delivered in 10 days, these would be used for detailed product testing and customer evaluation.

There was cause for celebration, when PSM announced that the prototypes had been very successful and well received!

Having made 3 small improvements to the design based on their evaluation; the 3D data was sent to one of Plunkett Associates tool makers for the manufacture of P20 tooling and first off samples.

Within 4 weeks T1 parts were in the hands of PSM and being assembled with electronics for final evaluation. A job well done!

Injection moulded box for marine application