CENTRAL FACILITY

One of the missions of IIT Kanpur is technology outreach to Indian industries. The Computer Aided Design (CAD) Laboratory has been successful in achieving this objective by bringing together under one roof all tools of product design and prototyping, and throwing open the doors of these fully functioning facilities to large and small industrial houses. DIRECTIONS brings you a brief report on the vision and growth of the CAD Laboratory at IIT Kanpur.

Computer Aided Design Laboratory

In 1984, IIT Kanpur initiated work to set up the CAD Laboratory; initial funding was received from the Department of Electronics, Government of India, and the United Nations Development Program. The laboratory promoted research (student thesis and sponsored projects), training and consultancy in the areas of computer aided design and computer graphics and simulation.

In the early 90s, the laboratory expanded its horizons to include the technologies of Rapid Prototyping, Rapid Tooling, Reverse Engineering and Simulation. Consider this: the ultimate goal is to make a machine element or a part. So, first make a solid model of it using CAD. Then, use a rapid prototyping machine and make the part directly using a computer controlled system. Next, a sample number of parts are required for testing. For this purpose, a mould in epoxy, silicone or a low melting alloy, is made quickly. Then, for inspection of these parts, a robot-based reverse engineering system is used to recreate the model based on the actual part made. And, finally, for analysis of these solid models, simulation is used in order to identify defects, if any, in the manufactured part.

Rapid Prototyping

A rapid prototyping machine produces parts in a layer by layer manner using a plastic material. A CAD model can be converted into a part in just a day or two!! No tools, no machining and no fixtures are required! To cater to the large demand from the industry, the laboratory is equipped with two rapid prototyping machines: FDM 1650 system of Stratasys and Soldier 4600 system of Cubital. The latter is a faster machine and it uses UV curable resin. These two machines, along with Unigraphics, Pro-engineer, IDEAS and AutoCAD software, provide the total design and prototyping environment.

Rapid Tooling

At the laboratory, a silicone vacuum casting machine of HEK Germany quickly produces a mould in silicone. Using this mould, polyurethane parts are cast. The life of one such mould is limited to a maximum of about 200 parts depending on the geometric complexity of parts. Epoxy moulds can be used for injection moulding, blow moulding, composite lay-up and vacuum forming processes. The moulds and patterns can be coated with cold metal spray, and can also be filled with steel or aluminium granules. When tooling is required for sheet metal components, a low melting alloy can be used to make a punch-die pair. This pair can be used in a press for making a limited number of parts of sheet metal compounds.

Reverse Engineering

The laboratory employs an arm (Faro Arm of Silver Series) with six-degrees of freedom to touch the part and digitise its surface. The needle-like probe of the arm generates a data cloud, which is then distilled by software like Anthrocam and Surfacer to create a CAD definition of the part. This arm is sometimes used to inspect the as-built part and compare with the design-level CAD model.

Simulation

Factory level simulation, layout planning and scheduling of activities are handled at the CAD laboratory by software like QUEST and Virtual NC. Stress Analysis of parts is done through SDRC-IDEAS, NISA, MATLAB and MACSYMA software. The rapid prototyping models are preprocessed using QUICKSLICE and DFE software.

In Closure

The CAD Laboratory has four faculty members associated with it along with a group of 25 graduate students and research engineers. They are pursuing research in areas like genetic algorithms; artificial intelligence and feature-based CAD modelling; controls; and computational geometry, intrinsic geometry, shape optimization and nesting. Projects sponsored by many national and international agencies are being executed by the faculty members. Today major international corporations like Autodesk, PTC, Computervision and SDRC, look to the CAD Laboratory of IIT Kanpur for guidance.

In the past five years, the CAD laboratory at IIT Kanpur has been successful in enlightening the professional community with new thoughts and techniques in the area of product design and prototyping.

For more details, please contact:

Professor Sanjay G. Dhande

CAD Laboratory

Department of Mechanical Engineering

IIT Kanpur, Kanpur 208016

Telephone: (0512) 59 7170; Fax: (0512) 59 7180

e-mail: sgd@iitk.ac.in

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