System Design Cycle: VI) Detailed Design

After doing the preliminary design and development of the machine the next important step is making the detailed design of the machine or product (see the fig below). This stage of the machine design cycle should not be confused or mixed with the previous stage of making the preliminary design. Many designers think that all the designing that has been done in the preliminary stage is quite sufficient, but this is a wrong notion. At the preliminary design stage certain changes can be made in the design, but once it has been finalized no further changes can be made. The details of the finalized design are worked out in the detailed design stage of the machine design cycle.

During the detailed design stage all the parts of the machine are defined clearly and also how they will work in tandem with each other to make a fully functional machine. The details are found out for all the parts right from the biggest parts of the machine to the nuts and bolts for the machine. There are no doubts left regarding the elements to be used in the machine, their size, strength, materials etc and how they will work. The working mechanism of the whole machine is defined in all the minute details.

During the detailed design stage the complete drawing of the assembly of the machine and all the individual machine elements of the machine is made. The drawings include all the dimensions of all the components, the permissible tolerance for manufacturing them, the materials for manufacturing and the method of manufacturing the components. Thus the detailed design comprises of all the detailed specifications of the whole machine as well as all the components or elements of the machine.

There are two important activities carried out during detailed design stage of machine design cycle, these are:

1) Detailing the parts, components, and their assembly.

2) Finalizing the details of methods of fabrication or manufacturing the machine and its components.

To complete the detailed design stage successfully the designer should have sound technical knowledge about the machine, its components, the materials to be used, the available manufacturing processes, the limitations and capacities of the machines etc. If the designer lacks in this knowledge, they should consult the competent authorities to get full information before carrying the process of detailed design. To successfully carry out the detailed design procedure it is desired that the designer has good knowledge of strength of materials, theory of machines, thermodynamics, fluid mechanics, electromagnetics, etc.

During the detailed design other factors to be considered are efficiency of the machine, safety margins, quality standards, appearance of the machines etc. Many times a good design has to be abandoned due to reasons like tooling, machining, and manufacturing processes. Hence considering all the relevant factors at this stage is crucial, because once the detailed design is done, the prototype of the actual machine will be made to see of it can work properly.

Book: Machine Design by Dr. P. C. Sharma and D. K. Aggarwal