Here from the start 1902: The first Engineering Building. 1930s: Belt Driven Machine Tools 1930s: Wind Tunnel Modelling 1955: The Aerofoil Workshop especially equipped for the manufacture of model aerofoils and wings 1960s: The Rolling Mill. 1960s: The East Group Design Office 1978: The Apprentice Training Workshop, Building 17 1986: Training an Engineering Apprentice in the West Design Office 1991: The West Workshop 2016: The Engineering Workshop in Module 12 2016: A Computer Numerically Controlled 4-axis Milling Machine. 2016: The Design Office equipped with a 3 Dimensional Computer Aided Design System called CATIA 2000-2016 1970-2000 1940-1970 1902-1940 1902: The NPL opening ceremony took place in the Engineering Building as it was the largest covered space on the site. From the very first day that the NPL opened there have been Engineering Workshops and Design Offices on site. The size, number and location of these engineering facilities may have changed over the years but the high quality of work and the unique design innovations produced has always remained a constant.
CAD: Computer Aided Design Office Technology Revolution Present Day Since the inception of NPL, in 1902, until the middle of the 1980 s a scene similar to that shown above would have greeted you if you visited the Design Office. Pencil, paper, drawing boards and the slide rule were the equipment of choice for the Engineering Designer In 1986 things changed dramatically, Computer Aided Design (CAD) arrived at NPL. Originally it was only used as a computerised 2D drawing board but very soon it s ability to model in 3 dimensions was exploited. Now the latest versions of CAD allow us to produce an array of outputs which have uses in areas that could never have been conceived of when it was first installed. Through the Monitor Designs can be reviewed in a 3 dimensional (3D) format, making the design much easier to interpret than before. They can also be sectioned as shown above. Persons reviewing the design are no longer required to have an knowledge of how to read technical drawings to understand the proposal. Portable 3D Images The designs can be exported into an Adobe 3D format. This powerful tool allows people to view the design in 3D on their own computer without the need for any CAD software to be loaded onto it. A Picture Is Worth A Thousand Words By placing design models in real life locations and creating photo realistic images confidence in the suitability and success of a design proposal can be greatly increased. It also assists our internal customers in their efforts to sell projects to external partners. Stress and Frequency Analysis Within the CAD system the stress, frequency response and strength profiles of components can be investigated under various loading scenarios. Space Planning The CAD system can be used to plan the installation and interaction of a new design with its surroundings. Ergonomics Using the 3D CAD system NPL Designers were able to confirm that the proposed mechanical manipulators had the required reach envelope. Two Dimensional (2D) Drawings 2D drawings are still the accepted way for the NPL Designers to communicate their manufacturing instructions to the NPL workshop and external contractors. Computer Aided Machining (CAM) Within the CAD system 3 dimensional machining cutting profiles can be created. These can then be used by CAM equipped machines to create shapes which would otherwise be very difficult or impossible to program directly on the manufacturing machine. Sheet Metal Package Items can be designed in 3D within the CAD system and then converted to 2D drawings and CAM files for our external sheet metal contractor. This reduces the manufacturing cost of the finished parts. Manufacturing Communication Analysis Customer Interaction The Way We Were
A Design Story The initial communication between the Scientist and Designer is The Design Brief. The Brief contains the customers project requirements. Aspects such as the scientific purpose, mode of operation, tolerance of movements, etc will be specified within. From the Brief an initial design is created. The design is then reviewed by the customer. This can happen several times as a design evolves. Once finalised the design is approved and detailed dimensioned drawings are created. These drawings are then passed to the workshop so that manufacture of the final product can take place. The Prototype. For the project we describe below, the aim was to create a piece of equipment which can produce pressure waves at various frequencies to simulate the arterial pressures measured in hospital patients. These pressure waves will then be used to calibrate the heart monitoring equipment found in Hospital Intensive Care Units. The customers design brief specified that the design should include a piston to produce a pressure wave. Mounted on to that piston were optical components which when combined with a laser, confirmed the movement profile of the piston. As the measurement technique had not been tried before a commercially available piston was used to minimise development time and cost. A screen image of the initial 3D design. This was used to review the design with the customer. Sectional views are a very useful aid when reviewing a design. The piston assembly drawing The manufactured assembly Evolution of the Design. The Prototype device was a success. There were some alignment problems which caused a sticking piston but it proved the measurement technique and that the design concept worked. Therefore it was decided that the design should evolve into a second device. The new design removed the alignment issues and a bespoke piston design has removed the sticking problem. A screen image of the new 3D design. The product assembly drawing. The new manufactured assembly
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Manufacturing Processes Milling Milling is the process of moving of a work piece against a rotating cutter. The cutter is able to cut on both its flanks and its tip. Milling machines may be manually operated or digitally automated via computer numerical control (CNC) Turning Turning is the process of moving a static tool against a spinning block of material to produce objects that have a symmetry about the axis of rotation. As with milling machines, lathes can be manually operated or digitally automated via computer numerical control (CNC). Grinding Grinding is the process of removing material using a rotating abrasive wheel to wear away the surface of a work piece. The main advantages of grinding are high accuracy, good surface finish and the ability to machine hard and tough materials that are not suitable for milling or turning. Electro Discharge Machining EDM or spark erosion uses the destructive effect of pulsed electrical discharge in a positive way to vaporise conductive materials. A similar effect can be seen with the erosion found on car spark plugs. Wire eroding uses a CNC controlled thin brass wire to cut highly accurate forms.