PRODUCT DESIGN

Design Problems

Design problems normally originate as some form of problem

statement provided to the designer by someone else, the client or the company management. These problem statements, normally called a design brief, can vary widely in their form and content.

At one extreme, they might be something like the statement made by President Kennedy in 1961, setting a goal for the USA, 'before the end of the decade, to land a man on the moon and bring him back safely'. In this case, the goal was fixed, but the means of achieving it were very uncertain. The only constraint in the brief was one of time - before the end of the decade. The designers were given a completely novel problem, a fixed goal, only one constraint, and huge resources of money, materials and people. This is quite an unusual situation for designers to find themselves in!

At the other extreme is the example of the brief provided to

the industrial designer Eric Taylor, for an improved pair of

photographic darkroom forceps. According to Taylor, the brief originated in a casual conversation with the managing director of the photographic equipment company for which he worked, who said to him, 'I was using these forceps last night, Eric. They kept slipping into the tray. I think we could do better than that.' In this case, the brief implied a design modification to an existing product, the goal was rather vague, 'that [they] don't slip into the tray', and the resources available to the designer would have been very limited for such a low-cost product. Taylor's re-design provided ridges on the handles of the forceps, to prevent them slipping

against the side of the developing-tray.

Somewhere between these extremes would fall the more normal kind of design brief. A typical example might be the following brief provided to the design department by the planning department of a company manufacturing plumbing fittings. It is for a domestic hot and cold water mixing tap that can be operated

with one hand. (Pahl and Beitz, 1984).

Engineering Design Methods

Strategies for Product Design

THIRD EDITION

Nigel Cross

The Open University, Mi/ton Keynes, UK

JOHN WILEY & SONS, LTD

Chichester- New York. Weinheim • Brisbane. Singapore. Toronto

Physical Properties of Metals

The physical properties of the metals include luster, colour, size and shape, density, electric and thermal conductivity, and melting point. The following table shows the important physical properties of some pure metals.

A TEXTBOOK OF Machine Design

(S.I. UNITS)

[A Textbook for the Students of B.E. / B.Tech.,

U.P.S.C. (Engg. Services); Section ‘B’ of A.M.I.E. (I)]

2005

EURASIA PUBLISHING HOUSE (PVT.) LTD.

RAM NAGAR, NEW DELHI-110 055

Selection of Materials for Engineering Purposes

The selection of a proper material, for engineering purposes, is one of the most difficult problem for the designer. The best material is one which serve the desired objective at the minimum cost. The following factors should be considered while selecting the material :

1. Availability of the materials,

2. Suitability of the materials for the working

conditions in service, and

3. The cost of the materials.

The important properties, which determine the utility of the material are physical, chemical and mechanical properties. We shall now discuss the physical and mechanical properties of the material in the following articles.

A TEXTBOOK OF Machine Design

(S.I. UNITS)

[A Textbook for the Students of B.E. / B.Tech.,

U.P.S.C. (Engg. Services); Section ‘B’ of A.M.I.E. (I)]

2005

EURASIA PUBLISHING HOUSE (PVT.) LTD.

RAM NAGAR, NEW DELHI-110 055

Structure For Cutting Machine

There is a machine where the object is not moving but it works like a machine moving his tools crab, felts auger (drill press), FRIS machine (milling machine) and grinding. There are also machines in which objects move, but his tools still works like a machine shaved machine, lathe (lathe), and FRIS boring (boring mills). Study the picture below that is the usual processes performed on the engine components.

In figure 2 below the basic structure seen in conventional machine tools. In figure A. rotating workpiece in a lathe, but the tools (cutting tools) silent. On boring machine (figure B) while the object rotates his tools still work. Or sliding sled delivers tooling to the workpiece is usually more fun than spinning on a rotating shift the workpiece on the tool head remains stationary. Figure C and D are respectively

crabs and penyerut machine. Form the structure of both machines is influenced by the size of the workpiece where the workpiece little more suited to be machined crab.

On mowers FRIS, the rotating tool is used only on the drill tool. FRIS machines widely used to cut circular hole, making pathways pegs, creating a gap, sawing, memfris slab and the surface, cut gears and to form the object whose shape is not common.

Figure 2 E is the machine where the tool rotates FRIS combined with the workpiece moving transversely.