Plastic Injection Moulding Specialists. Est 1948.

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

At S.B.Weston we will always encourage prototyping of your product in order to realise design aspects which can not be fully appreciated through computer rendered models. Prototypes are valuable for gaining an insight into how the product will perform and what its limitations and weaknesses may be. Understanding problems from a prototype allows the design to be easily be amended well in advance of tool production.

There are many available prototyping methods. We can machine plastics, wood or metal and where possible we will always work in the same materials as the intended final production version. Ensuring that the functional and stylistic aspects of the prototype are acurate to the production version is of optimum importance.

We transmit CAD information from files supplied by our designers, directly into our HERCO CNC milling machine allowing us to work on prototypes very quickly and accurately.

There are certain types of product where we will use Vacuum Forming instead of the traditional milling from a solid process. The process is most commonly used to produce product packaging using a material such as HIPS High Impact Polystyrene but is also very effective for many types of prototypes.

In the past we have manufactured prototypes using methods such as  Stereo Lithography.

Tags: CAD Component Design, Design, Prototyping, Stereo Lithography, Technology, Vacuum Forming

Let us visualise your idea!

S.B.Weston’s design team can provide you with a technical drawing service using the latest CAD software.

Our designers will work with you to evolve and improve your product idea aesthetically and functionally creating 3D models and detailed drawings to visualise your idea on screen.

To ensure your product can be successfully transferred to a mould tool which moulds, ejects and generally performs correctly and consistently at the manufacturing stage, the following design considerations will be applied:

• consistent wall thicknesses throughout the design.
• thin walls to allow consistent cooling and reduce uneven material
• shrinkage.structures such as ribs utilised to strengthen walls.
• ribs – half the wall thickness to avoid sinking.
• corner and edge radii.
• draft angles added to sides (typically up to 2 deg) – especially textured /spark eroded walls and walls higher than 1.5cm.
• no undercuts that are impossible to remove from the mould unless absolutely necessary – undercut features nescessitate side core actions which significantly increase the complexity and cost of the mould.
• light colours and spark eroded finishes to hide flow patterns.
• keeping holes at least .0.75cm from edges.

Once these criteria are met we will look for a design approval from you, at which point the CAD files will be supplied to our toolmaking staff for prototyping or CAD/CAM tooling purposes.

Remember… Design will make or break a product… come to the professionals!

Tags: cad cam tooling, CAD Component Design, Drawing, Injection Moulding Technology, Prototyping, Technology

Let us take your product idea from sketch to prototype to production!

Project management

We specialise in project management, and are more than happy to guide you through all aspects of design and development applying our knowledge of the constraints of the injection moulding process along the way.

CAD Component Design

Our experienced in-house CAD component design team will take your ideas and sketches and turn them into fully rendered 3D CAD models producing acurate drawings detailing all aspects of your product.

Prototyping

We have prototyping facilities on site. The building of a prototype during the design process is essential in order to fully comprehend the product and iron out any potential weaknesses that it may have.

Let us resolve your product idea and reveal its full potential!

Tags: CAD Component Design, Project Management, Prototyping