Plastic Injection Moulding Specialists. Est 1948.

Beautifully packaged stereo card series with stereoscope

30 Oct 2009
By Alison Scott (London,United Kingdom)
‘The stereoscope is much better than any other I’ve ever seen bundled with a book. I’m not very knowledgable about lenses and so on, but I found it easy to use and well designed’

A Village Lost & Found

23 Oct 2009
By Markus Wanner (Switzerland)
‘It has many stereo pictures to look at and with this wonderful high quality owl stereoscope (designed by Brian May himself!)’

Much more than a wonderful Book!

25 Oct 2009
By Claudia Manzoni (Italy)
‘The accompanying stereoscope is a very special instrument, carefully designed, very easy to use, adjustable and versatile. And it is also a nice object to look at: I am amazed at how smart and classy a plastic-made, fully functional stereoscope can be! Its use is not to be limited to this book at all: it works perfectly to view old and new stereopictures, and also the ones you can easily take yourselves, following the simple hints in the book… it is magic! It is also very useful to view 3-D pics on a pc screen in my opinion – if you don’t mind some sort of `mosquito-net’ effect due to the low resolution of the screen.
In conclusion… a charming book that will certainly delight you and an outstanding stereoscope that you can’t miss!’

see more reviews here

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.

Prototypes

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.

Tooling

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.

Manufacturing

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 colours 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.

Conclusion

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.

Tags: Brian May, Cad Cam Tooling, CAD Component Design, Injection Moulding, Polypropylene, Stereoscopic Viewer

Brief

Westons were asked to design and build a glovebox housing for a DVD multichanger to be installed as an option in the new Mini Cooper. The design had to mimic the cars interior and fit perfectly into the glove box recess. For security reasons the unit needed to be sealable and discreet.

Component Design

It was decided that the unit should be made using the vacuum forming process and not plastic injection moulding, mainly because of the small quantity requirement which would not justify the tooling expense that injection moulding would demand. The vacuum formed part was supported and attached to the car using metal brackets which Westons designed and sourced. A roller shutter door was installed on the front of the unit to conceal it when not in use. The unit was designed to follow the contours of the car with production versions produced in material the same colour as the cars interior.

Conclusion

The product was safety tested and approved for production. Several hundred were produced.

Brief

The brief was to design a chiller door handle replicating the packaging design of the Sunny Delight product.

CAD Component Design

CAD drawings submitted for client approval were sufficient for the client to OK the manufacture of prototypes.

Manufacturing

1 . Replica bottle in clear polycarbonate – front half only, open at top and back.

2 . The lid moulded with the bottle in the same material.

3 . Mounting bracket punched and formed in steel, finished in black polyester powder coat. Component mounts the handle to the door of the chiller. It provides strength for the handle when the moulded front is screwed to it. Lid is positioned last, linked to the bracket by a screw passing right through both components.

The plastic parts of the prototypes could not easily be made from polycarbonate, the proposed production material. the nearest alternative material was used. This was P.E.T. which had the necessary clarity and was easy to vacuum form into the shapes required. Vacuum forming moulds were made, for bottle and lid.

Our metalworking department was producing samples of the mounting bracket, which for the prototype was sprayed black.

We were thus able to deliver prototypes in ten days from receipt of order. Once approval of prototype was received, design and manufacture of the injection mould for bottle and lid was planned. The completion of the job being the production of the mounting bracket. This last process was straightforward as the C.A.D. – C.A.M. details were already available from the prototype.

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 - to determine whether parts of the original could be incorporated. The shape was to remain the same, the new requirements for the interior were such however, that none of the original 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.