Injection Moulded Part Design

Injection molding has been one of the most popular ways for fabricating plastic parts for a very long time. They are used in automotive interior parts, electronic housings, housewares, medical equipment, compact discs, and even doghouses. 

Injection Moulded Part Design is one of Devon 3D CAD’s core skills. All the parts I have designed for plastic injection moulding have required a lot of thought and development before reaching the stage of finalising their design for moulding. Here is a selection of the plastic part I have designed.

Protimeter, A suite of hand held moisture meters.

Protimeter Timber Mini, designed and engineered by Neil Taylor Protimeter Hygromaster designed by Neil Taylor at Devon 3D CAD Protimeter lighted scale on Moisture Meter designed by Neil Taylor at Devon3D CAD Protimeter Moisture Meter designed by Neil Taylor at Devon 3D CAD

Protimeter’s electronics designer updated the capabilities of the Moisture Meters and Hygrometers by revising the circuit boards and sensors. This was a good time to modernise the enclosure design which I was asked to carry out. This encompassed Product Design and engineering Design. My brief was to use as many common parts as possible for a suite of new products. I used a clam shell set of parts with a soft grip plastic between the top and bottom casings. The products were prototyped using SLA parts and I sourced the injection moulding company in China.

Psion Dacom

Psion Dacom Gold Card ISDN Adapter

This ISDN Adapter for Psion was a landmark design for me. It was the first product I modelled and engineered using SolidWorks 3D Solid Modelling software.

A good start. I have immensely enjoyed using SolidWorks since I plunged headlong into the 3D world.

Mars Electronics, MEI Cashflow 7000 Series Coin Mechanism.

Working in a large design team is exciting and exhausting at the same time. Exciting because as a team you are creating something special – beyond the capabilities of one person – and exhausting because you must keep up with the pace of the team, not wanting to be the one bringing up the rear as the deadline approaches. Designing  coin changing mechanisms relies on a great deal of legacy knowledge and experience but putting this into practice with the goal of using nearly all plastic injection moulded parts.

It was a steep learning curve for me, having no previous knowledge of coin changers, but I was up for the challenge. The Acoustic Module that I was designing, was crucial to the aim of being able to audit the value of coins in the machine at any time. The principle behind determining the height of coins in each of 5 tubes of different denominations (from which you could calculate the coin value) had not been verified. It involved making a spike of sound (by initiating a spark between two electrodes) and directing the sound through closed tubes to the top of each tube and measuring the time taken for the sound to bounce off the top coin and back to the top of the tube using tiny microphones !!!! After many versions of SLA parts, the measuring algorithms were good enough to accurately and consistently measure the distances for each coin tube.

Injection Moulded Part Design.

The Acoustic Module I designed was the most complex set of moulded plastic parts I have attempted and I am proud to say they did a good job. The clam shell provided 5 small tubes for the sounds to travel from the spark generator to the top of each tube. There were moulded cable clips to route the cable harness and various covers. Positioning the critical points was a nightmare because positions of systems above and below the Acoustic Module were changing day by day. But all was right at the end.

MEI Cashflow 7000 Acoustic Module Injection Moulded Part Design by Neil Taylor at Devon 3D CAD

Acorn Computers – Phoebe 2100 a RISC PC tower Design

Acorn Computers was a hugely popular and influential British computer designer and manufacturer in the 1980-1990s.

I was commissioned to engineer and model the front panel for this zingy tower product. Little did I know that this was the last computer they would produce. It was cancelled as the finished products were on the high seas to England in September 1998. I am still proud to have played va part in the  development of Acorn’s last computer.

Tannoy, Loudspeakers

I designed and engineered a set of satellite speakers and subwoofer for Tannoy while working at a London design consultancy. I started from a GA from the product designer and modelled the speaker cases to be injection moulded plastic. The shape was based on a complex set of ellipse profiles. The satellite speakers were designed to have three different mounting styles: surface mount, wall mount and stand mount and was achieved by using a separate moulded mounting feature.

Tannoy Arena Series 11 engineered and CAD modelled by Neil Taylor      Tannoy Arena speaker set Injection Moulded Parts designed by Neil Taylor at Devon 3D CAD

Plastic part design for RTC Europe.

RTC designs and manufactures a variety of systems for vending machines. The object is to always place products at the front of a shelf. Usually this is achieved using low friction plastic moulded tracks and constant force springs. These can be housed in vending machines or on deep shelves.

I revised a series of systems to adapt them for different sized products and multiple sliding tracks that can be clipped together.

Injection moulded beverage vending track - revisions by Neil Taylor at Devon 3D CAD  BevTrac jar holders for RTC, revised and CAD modelled by Neil Taylor

Tuflok Tape Measure.

I modelled and engineered this toughened tape measure as a plastic clam shell casework with an overmould of compressible grippy plastic.

TUF-LOK Rugged Tape Measure for Fisco, engineered by Neil Taylor