‘The Raspberry Pi is a credit card sized single-board computer developed in the UK by the Raspberry Pi Foundation with the intention of stimulating the teaching of basic computer science in schools.’

RS Components, one of the two electronics companies responsible for production and marketing of the Raspberry Pi in the UK, approached S.B.Weston Ltd, a UK based plastic injection moulding company, having seen their range of WestonBoxes at a packaging trade show. They asked Westons to produce a plastic box for the Pi, similar in design to their plastic business card wallet, but modified so that it would securely hold the Pi board with an SD card inserted.
Westons worked with RS to design an injection moulded polypropylene case that would protect the Pi during shipping and provide the end user with a neat way of storing the otherwise unprotected board. The requirement was not for the case to be air tight, just for it to be as protective as possible from the effects of static electricity, moisture and dust.
RS requested that the Pi should be fully located in the case, not clipped in, and should not need to be lifted out of the case in order to plug in any of the peripheral devices, or to operate. These requirements were satisfied with the inclusion of retaining hooks and an additional hinge, allowing the case to open flat, giving unrestricted access to the sockets on the board.
Westons had several SLS prototype models produced, and from these were able to get an approval on the design from RS. A 2 impression mould was commissioned and produced, and 6 weeks later the first pre-production mouldings were run.
Production is now well under way at the S.B.Weston Ltd. plant in Sunbury-on-Thames, West London, and the first batch of 200,000 Pi cases are to be distributed before Christmas with all Pi’s ordered from RS Components as of now.
Reid Weston, company director at S.B.Weston Ltd. Said, “Its great to be involved in such a high profile project, especially one like this which is all about British technology and manufacturing.

A client approached us with an idea he had successfully patented for a one piece plastic hole punch. He had been granted a patent due to several innovative design features, the most significant being that the base of the punch folded over to create a tray to catch the punched paper, as a conventional hole punch does. The product’s other unique features were its size, weight and a fold out tab which allowed it to be clipped on to the rings of a binder, hence the name Infolda.
To produce the product as a one piece moulding we were constrained to Polypropylene as a material. Polypropylene is the only suitable plastic for moulding live hinges on a component. Any other material will snap or crack under the repetitive stresses put on a hinge.
Concerns were raised about the suitability of polypropylene with regards to the punch heads, the concern being that the punches could become blunt and cease cutting the paper. We decided that if this did occur during testing, that the application of brass or steel punch heads to the moulding at the time of manufacture was a viable solution that would ensure the punch remained effective. We decided that we could work with this solution as a plan b if the plastic punches didn’t last, and began developing the prototype supplied by the client into a finished design capable of being injection moulded.

Design / Developmemnt
The client had built a crude prototype demonstrating the size and shape of the product. We took the model and from it created drawings and an evolved 3D CAD model – applying all the necessary considerations to make the product suitable for injection moulding. Once we had a design we were all happy with, a polypropylene prototype was machined in house using a CNC process. This method of prototyping in polypropylene enabled us to create the 3 live hinges which were to be present in the final design.
Many tests were applied to the prototype in order to refine the design, the bulk of which revolved around the suitability of Polypropylene for the punch heads. Eventually it was decided that plastic was not suitable for the punches, and so metal punch heads were designed to be applied at the time of manufacturing. It was decided that this was preferable to polypropylene punch heads although there were additional costs involved. The design was approved with by the client with metal punches, and so we went ahead and commissioned a mould.

We advised our client that an Aluminum mould would be suitable, given that at this point, negotiations with buyers from major supermarkets and stationery companies were underway, but had not yielded any large orders. An aluminium tool saves time & money in the toolmaking phase, and would be adequate for manufacturing small to medium sized runs of hole punches as the project got moving. If demand suddenly increased, we could go ahead and commission a multi-impression tool made from fully hardened steel which would survive runs of millions of mouldings. Our toolmaker provided us with a tool GA drawing which we checked and approved. The tool was finished and up and running with us in about 6 weeks.

The initial runs of the infolda were manufactured at S.B.Weston’s plant in Sunbury. The idea was to run enough stock for promotional purposes and for the clients sales team to generate interest amongst the stationery buyers. At this stage a full production run has not occurred.

The client was very happy with the final product, but unfortunately no large orders have been forthcoming… yet. S.B.Weston Ltd are ready to manufacture, and once we get the go ahead from the client and his sales team, we can go into full production. In the meantime we are happy to store and maintain the mould.

Project Brief

In 2009 Westons were approached by Queen guitarist Brian May who planned to publish a book on the stereoscopic photographs of TR Williams. It was proposed that the book would reproduce Williams’ stereoscopic series ‘Scenes In Our Village’, and so would require a flat packing plastic stereoscope included with the book to enable the reader to view the pictures in 3D. Brian had been unable to source a stereoscopic viewer that he was happy with, and so came to Westons with the intention of putting his own viewer design into production.

Having already produced card prototypes, Brian had a firm idea of what he wanted from his viewer, what he did not know was exactly how the injection moulding process would work for the design, what the benifits and pitfalls would be, and what considerations would need to be taken into account in order that the injection moulding manufacturing process would be successful.

CAD Component Design

We began the project working closely with Brian and co-author Elena Vidal to develop what became the OWL viewer, modeling it using CAD software and eventually resolving the design as a two piece polypropylene moulding with snap fit lenses to be inserted at the time of manufacture.


The development stage involved several prototypes. The most important being a polypropylene model with fully functioning hinges (of which there were 6), runners and snap in lenses. This prototype model was CNC machined from sheet polypropylene on our Hurco, giving a very accurate indication of how the final moulded version would behave.


The design was approved from the prototypes and on Brian’s request we began tooling here in the UK in our onsite workshop.

The fixed half core insert plate set up on our Bridgeport Milling machine for the drilling of ejector pin holes.

An eyepeice core showing the tracks created by the CNC milling program.

Spark Erosion of an eyepiece core. A copper electrode is lowered onto the steel and an electrical current passed through it. The result is perfect erosion in the form of the copper electrode.

The OWL tool features two laser cut inserts. The London Stereoscopic Company Logo was cut from CAD files supplied by Brian which used the original London Stereoscopic Company artwork.

Brian May, Elena Vidal and Reid Weston viewing test mouldings. 5 mould trials occoured before production took place. The tool was designed with certain tolerances in place which were tweaked minutely to perfect the stiffness of all of the clips, the runners and the snap in lens fit.

Elena Vidal, Brian May and Tony Weston reviewing test mouldings.

Brian May, Elena Vidal and Chris Dodman with the final book and viewer.


Brian requested that the material colour should change during the run and so 15 different colour masterbatches were mixed into the virgin material sequentially. All mouldings were used including the ones produced as one colour mixed into another. It took S.B.Weston only a few days to manufacture and assemble the 8.8k multicoloured viewers for the books initial run.


The OWL Stereoscopic Viewer project came to a successful conclusion for S.B.Weston Ltd as we despatched the 8.8k mouldings for packaging into the book slipcase having met our deadline. The most important aspect being that Brian was very happy with the final product, which is now getting very good reviews – the book is still in the Independent top ten book list a month after release.

Brief – Royal British Legion Poppy Appeal

We manufacture approximately 1 million poppy parts for the Royal British Legion each week. The components we produce are

    • Poppy Stems
    • Poppy Buttons
    • Large Poppy Stamen
    • Remembrance Crosses


All our poppy components run from multi impression tools produced by our team of in house tool designers and engineers.

Quality Control

The moulded components are subject to strict quality control standards as they are sent to the Poppy Factory in Richmond upon Thames where they are put through a sensitive robotised production process. Any deviations in the size or weight of the mouldings can disrupt the process and cause delays in the production schedule.

Mercedes S500 Carphone Armrest – Brief

Design replacement armrest compartment with roller shutter cover enabling a telephone to fit inside. product required to fit into position of standard armrest and look as per original equipment.

Design Assesment

We accessed the existing components to determine whether parts of the original could be incorporated. The overall shape was to remain the same, but the new requirements for the interior were such though that none of the original armrest parts could be used.

Production Report

It was estimated that sales would be hundreds rather than the thousands, so injection Moulding was ruled out due to high tooling costs. It was decided to manufacture using vacuum forming, a process with low tooling costs

A design was drawn up from the original Mercedes armrest and moulds for the external shapes were cast in resin, the moulds for the roller shutter housing, were machined in aluminium.

the first pulls from the new moulds were produced, routing and trimming jigs were then made to machine the components to their final dimensions.

There were two components which were impossible to produce by vacuum forming. – the trim which
retains the roller shutter, – the handle of the roller shutter itself. The styling and shapes
specified by the client, and the requirement for these parts to have a smooth finish as moulded,

To produce the best finish by soft feel painting, it was decided that the only satisfactory method of production would be to injection mould.

First tests of the finished armrest revealed that some reinforcement was required in the area of the hinge, because the large recess necessary for the phone had taken away some of the strength that the original had in that area. This problem was satisfactorily resolved by riveting a shaped steel brace into the structure.

The roller shutter was taken from stock, the extrusion having been designed for earlier projects.
All that was necessary was to cut the slats to length and assemble.

Dynamic tests in a car revealed the need for a catch to prevent the roller shutter from sliding open under heavy braking. This problem was resolved by building in 2 small powerful magnets into the slats of the roller shutter which were gripped by two others in the body to hold the shutter firmly in the closed position.

The finishing of the armrest required that the inside of the telephone compartment was flock sprayed black, the roller shutter and its retaining trim spray painted and soft feel lacquered, in the colour to match the trim of the vehicle in which it was to be fitted, and the body upholstered in matching leather; this last operation being carried out by the client.