This document provides an introduction to machine design and its various considerations. It defines machine design as the process of engineering design that involves designing machine elements and arranging them optimally to obtain useful work. Some key points covered include:
- Classification of machine design types including adaptive, development, and new design.
- Factors to consider in machine design such as material selection, forces on elements, size, shape, weight, manufacturing method, reliability, and cost.
- The general procedure of machine design including need identification, mechanism synthesis, force analysis, material selection, element design, modification, and drawing production.
- Considerations for manufacturability such as reducing part counts, modular design, and designing for
Design against fluctuating loads, stress concentration, Goodman and Modified Goodman Diagrams, Factors affecting stress concentration, Use of charts for finding stress concentration facotrs
Design against fluctuating loads, stress concentration, Goodman and Modified Goodman Diagrams, Factors affecting stress concentration, Use of charts for finding stress concentration facotrs
A tool that has a single point for cutting purpose is called single point cutting tool. It is generally used in the lathe machine, shaper machine etc. It is used to remove the materials from the workpiece.
Unit 6- spur gears, Kinematics of machines of VTU Syllabus prepared by Hareesha N Gowda, Asst. Prof, Dayananda Sagar College of Engg, Blore. Please write to hareeshang@gmail.com for suggestions and criticisms.
Dynamo meters are the electronic devices that are widely used to the purpose of force analysis in various field of operations. There is various types of dynamometers such as
Lathe tool dynamometer
Milling tool dynamometer
Drilling tool dynamometer
difference of NC and CNC ,Part programming,Methods of manual part programming,Basic CNC input data,Preparatory Functions ,Miscellaneous Functions,Interpolation:Canned cycles:part programming on component,Tool length compensation,Cutter Radius,Task compensation:Types of media of NC
,
diploma mechanical engineering
,
mechanical engineering
,
machine design
,
design of machine elements
,
knuckle joint
,
failures of knuckle joint under different streses
,
fork end
,
single eye end
,
knuckle pin
Definition, Use, Types of beariings, Types of Journal bearing, Materials for journal bearing, Failures of journal bearing, Design terms for journal bearing, Types of roller contact bearing, applications of roller contact bearing, Designation of roller contact bearing, Design terms for roller contact bearing, comparison between journal and roller bearings, characteristics of bearings, selection procedure of bearings
A tool that has a single point for cutting purpose is called single point cutting tool. It is generally used in the lathe machine, shaper machine etc. It is used to remove the materials from the workpiece.
Unit 6- spur gears, Kinematics of machines of VTU Syllabus prepared by Hareesha N Gowda, Asst. Prof, Dayananda Sagar College of Engg, Blore. Please write to hareeshang@gmail.com for suggestions and criticisms.
Dynamo meters are the electronic devices that are widely used to the purpose of force analysis in various field of operations. There is various types of dynamometers such as
Lathe tool dynamometer
Milling tool dynamometer
Drilling tool dynamometer
difference of NC and CNC ,Part programming,Methods of manual part programming,Basic CNC input data,Preparatory Functions ,Miscellaneous Functions,Interpolation:Canned cycles:part programming on component,Tool length compensation,Cutter Radius,Task compensation:Types of media of NC
,
diploma mechanical engineering
,
mechanical engineering
,
machine design
,
design of machine elements
,
knuckle joint
,
failures of knuckle joint under different streses
,
fork end
,
single eye end
,
knuckle pin
Definition, Use, Types of beariings, Types of Journal bearing, Materials for journal bearing, Failures of journal bearing, Design terms for journal bearing, Types of roller contact bearing, applications of roller contact bearing, Designation of roller contact bearing, Design terms for roller contact bearing, comparison between journal and roller bearings, characteristics of bearings, selection procedure of bearings
Machine Elements - company presentationKaran Asrani
A leading manufacturer of Machine Tool Accessories under the brand name 'STRIBECK'. Some of the products manufactured include Revolving Centres, Keyless Drill Chucks (capacity : 1/4" and 1/2"), Pipe Centres (upto 500mm dia), Dead Centres (Plain, Carbide Tipped and HSS), Collets and Collet Adaptors, Reduction sleeves, Extension Sockets, Stub Arbours and Long Milling Arbours and CNC Toolings.
We also re-condition old HMT, BFW and other imported milling, drilling, lathe and grinding machines and the replacement spares for the following machines are available with us:
HMT MILLING - FN2 - FN3 - M2 - EM3 - EM4 - FH3 - FV3 - E2
CYLINDRICAL GRINDING - G13 - K130 - G17
LATHE - LB 17/20/25 - H22 - H26 - NH 22 - NH 26 - LTM 20 - LBS 17, VIKRAM LATHE
RADIAL DRILL - RM 61/62/63/65 - COLUMN DRILL TYPE
BFW MILLING NO. 1 - NO 1.5 - NO 2. - NO. 3.0 - NO. 3.5
KIRLOSKAR LATHE – TURN MASTER SERIES, ENTERPRISE SERIES (1330, 2215, 1550, 1675, 1810), SHIMOGA LATHE, BOMBAY LATHE
HORIZONTAL BORING - HMT AZ9 - AZ11
ARGO & M1TR MILLING
We also manufacture machinery spares and accessories based on a customers drawing / specifications / sample.
Design 101
http://goo.gl/wIql8w
Week 2
Machine Element Design New Approach
Course Objective
===============
This is a fundamental course to discuss the criteria of Mechanical Design for both machine elements design and product design .
The course will discuss the design as a process in making a lot of products by terms of manufacturing , sustainability and environmental aspects
The Course is online and free to all
Instructor
Mohamed Mostafa Adam
This course was presented by PED 2016
Production Engineering Department - Faculty of Engineering - Alexandria University - Egypt
MFG 240 - Manufacturing DesignFinal ProjectScope of Project.docxARIV4
MFG 240 - Manufacturing Design
Final Project
Scope of Project
You must develop a manufacturing plan to machine the part to the final dimensions. The company is a small company of about 30 workers currently.
Product Design
You will design 1 tensile test bar using the following diagram
Develop a part print WITH tolerancing for this part
Material Cost
The raw material will be a material you specify. It will come as 1 diameter bar stock at a length you specify
Labor Cost
The labor cost for your plant is $15 per hour for all employees, except maintenance personnel, which cost $22 per hour.
Volume
Your manufacturing facility must provide 200,000 of the tensile test specimens
The equipment will be a stand alone cell or line. No other parts will flow though this area at this time.
Operational Plan
The facility is scheduled to operate 250 days per year and run two 8 ½ hour shifts per day. The workers must be given 30 minutes for lunch and two 15-minute breaks. The product life cycle is expected to be 5 years or more.
Reports
Reports must be written using a word processor and spreadsheet when appropriate. All drawings must be completed using CAD.
1) Title Page
2) Table of Contents
3) Executive Summary
4) A written report detailing the manufacturing plan. The individual manufacturing deliverables must support all information presented in the manufacturing plan summary.
i) Part prints (components plus assembly)
ii) Initial investment required and projected cost per part
iii) Conclusions, Recommendations
5) Manufacturing Plan Deliverables including all supporting data
Manufacturing Plan Deliverables
TAKT Time Calculations - TAKT is a German word for pace. TAKT time is the rate at which your customer requires the product. TAKT time defines the manufacturing line speed and the cycle time for the manufacturing operations. TAKT time is computed as:
Available work time per day / Daily required demand (parts/day)
Design Cycle Time Calculations – Design cycle time is the cycle time at which you design your manufacturing operations after considering contractual breaks, setup time, planned maintenance, estimated downtime, reject rates, etc. All of the items above reduce your actual work time available per day and reduce the required cycle time. Each team must also consider the reject produced by the system and increase the required production to offset the loss. The team must report the manufacturing cells planned operational availability. Operational availability is the Planned operating time /Available work time.
Process Plan Block Diagram – After reviewing the product prints, develop a process plan block diagram that represents the product flow through the various machines and processes. Include equipment, material handling, material flow, quality checks, repair loops, etc..
Equipment Sequence of Operations and Balance Chart – Develop a detailed step-by-step sequence of operations for each process or piece of equipme ...
Detail proposal of project including activities such as Deliverables, Scope, Resources, Proposed Approach, Scheduling in Microsoft Project, Costs, Potential Problems, Critical Path Analysis, Linear Responsibility Chart, Evaluation Methods and Budget.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
2. • Design is to formulate a plan satisfy a particular need and to
create something with physical reality.
• Realization of a concept or idea into a configuration.
• Design is the creation of a plan or convention for the
construction of an object, system or measurable human
interaction .
What is design????
3. • Machine is defined as a combination of resisting bodies with successfully
constrained relative motions which is used transform other forms of energy
into mechanical energy or transmit and modify available energy to do some
useful work.
• An apparatus using mechanical power and having several parts, each with a
definite function and together performing a particular task.
• Semi or fully automated device that magnifies human physical and/or
mental capabilities in performing one or more operations.
What is Machine???
4. • Machine is a combination of several machine elements
arranged to work together as a whole to accomplish specific
purpose.
• Machine Design involves designing the elements and arranging
them optimally to obtain some useful work.
• Machine design is the process of engineering design.
A machine is made up of mechanisms that work together to
satisfy the requirements of what the machine needs to
accomplish.
What is Machine Design???
6. 1) Adaptive Design:- The designer’s work is concerned with adaptation
of existing design. The designer only makes minor alternation or
modification in the existing designs of the product.
2) Development Design:- This type of design needs considerable
scientific training and design ability in order to modify the existing
design into a new idea by adopting a new material or different
method of manufacture. The designer starts from the existing design,
but final product may differ quite markedly from the original product.
3) New Design:- This type of design needs lots of research, technical
ability and creative thinking.
Types of Machine Design
7. Classification of Machine Design
Types of design
based on
method
Rational
Design Empirical
Design
Industrial
Design
8. 1) Rational Design:- Based on determining the stresses and strains
of components and thereby deciding their dimensions. This type
of design depends upon mathematical formulae of principal of
mechanics.
2) Empirical Design:- This type of design depends upon empirical
formulae based on the practice and past experience .
Types of Design based on method
9. 1) Industrial Design:- This type of design depends upon the
production aspects to manufacture any machine component
in the industry. Based on industrial considerations and norms viz.
market survey, external look, production facilities, low cost, use
of existing standard products
Types of Design based on method
10. What device or mechanism to be used???
To decide the relative arrangement of the constituent
elements.
Material
Forces on the elements
Size
Shape and space requirements
Weight of the product
Factors to be considered in
Machine Design
11. The method of manufacturing the components and their
assembly.
How will it operate.
Reliability and safety aspects.
Inspectibilty
Maintenance
Cost and aesthetics of the designed product.
Factors to be considered in
Machine Design
12. General procedure in Machine
Design
Need or Aim Synthesis (Mechanisms) Analysis of forces
Material SelectionDesign of Elements
Modification Detailed Drawing
Production
13. • Standardization is defined as obligatory (or compulsory) norms,
to which various characteristics of a product should comply (or
agree) with standard.
• The characteristics include materials, dimensions and shape of
the component, method of testing and method of marking,
packing and storing of the product.
• A standard is defined as a set of specifications for parts,
materials or processes. The objective of, a standard is to reduce
the variety and limit the number of items to a reasonable level.
Standardization
14. • On the other hand, a code is defined as a set of specifications
for the analysis, design, manufacture, testing and erection of the
product. The purpose of a code is to achieve a specified level
of safety.
• There are three types of standards used in design :-
Company Standards: They are used in a particular company or
a group of sister concerns.
Standardization
15. National standards:
– India - BIS (Bureau of Indian Standards),
– Germany - DIN (Deutsches Institut für Normung),
– USA - AISI (American Iron and Steel Institute) or SAE (Society of Automotive
Engineers),
– UK - BS (British Standards)
International standards: These are prepared by the International
Standards Organization (ISO).
Standardization
16. Standards for Materials, their chemical compositions, Mechanical
properties and Heat Treatment:
For example, Indian standard IS 210 specifies seven grades of grey cast iron
designated as FG 150, FG 200, FG 220, FG 260, FG 300, FG 350 and FG 400. The
number indicates ultimate tensile strength in N/mm2.
Standards for Shapes and dimensions of commonly used Machine Elements:
The machine elements include bolts, screws and nuts, rivets, belts and chains, ball
and roller bearings, wire ropes, keys and splines, etc
For example, IS 2494 (Part 1) specifies dimensions and shape of the cross- section of
endless V-belts for power transmission.
The dimensions of the trapezoidal cross-section of the belt, viz. width, height and
included angle are specified in this standard
Standards are used in mechanical
engineering design
17. Standards for Fits, Tolerances and Surface Finish of Component:
For example, selection of the type of fit for different applications is illustrated in IS
2709 on 'Guide for selection of fits'.
The tolerances or upper and lower limits for various sizes of holes and shafts are
specified in IS 919 on 'Recommendations for limits and fits for engineering'.
IS 10719 explains method for indicating surface texture on technical drawings.
Standards for Tes ting of Products:
These standards, sometimes called 'codes', give procedures to test the products
such as pressure vessel, boiler, crane and wire rope, where safety of the
operator is an important consideration.
For example, IS 807 is a code of practice for design, manufacture, erection and
testing of cranes and hoists.
Standards are used in mechanical
engineering design
18. Reductions in types and dimensions of identical components (inventory
control).
Reduction in manufacturing facilities.
Easy to replace (Interchangeability).
No need to design or test the elements.
Improves quality and reliability.
Improves reputation of the company which manufactures standard
components.
Sometimes it ensures the safety.
It results in overall cost reduction.
Benefits of Standardization
19. With the acceptance of standardization, there is a need to keep the
standard sizes or dimensions of any component or product in discrete steps.
The sizes should be spread over the wide range, at the same time these
should be spaced properly.
For example, if shaft diameters are to be standardized between 10 mm and
25 mm, then sizes should be like : 10 mm, 12.5 mm, 16 mm, 20 mm, 25 mm and
not like : 10 mm, 11 mm, 13 mm, 18 mm, 25 mm.
This led to the use of geometric series known as series of preferred numbers
or preferred series.
Preferred series are series of numbers obtained by geometric progression
and rounded off.
Preferred Numbers
20. • There are five basic series with step ratios of:
5
10 ,
10
10 ,
20
10 ,
40
10 &
80
10
• These ratios are approximately equal to 1.58, 1.26, 1.12, 1.06 and 1.03.
• The five basic series of preferred numbers (known as preferred series)
are designated as: R5, R10, R20, R40, and R80.
• The examples of preferred number series are: standard shaft diameters,
power rating of coupling, center distances of standard gear boxes, etc.
Preferred Numbers
21. • The difference in two successive terms has a fixed percentage.
• It provides small steps for small quantities and large steps
for large quantities.
• The product range is covered with minimum number of
sizes without restricting the choice of the customers.
Advantages Preferred Numbers
22. • The difference in two successive terms has a fixed percentage.
• It provides small steps for small quantities and large steps
for large quantities.
• The product range is covered with minimum number of
sizes without restricting the choice of the customers.
Advantages Preferred Numbers
24. • In a present days of buyer's market, with a number of products available in
the market are having most of the parameters identical, the appearance of
product is often a major factor in attracting the customer.
• This is particularly true for consumer durables like: automobiles, domestic refrigerators,
television sets, etc.
• Aesthetics is defined as a set of principles of appreciation of beauty. It deals
with the appearance of the product.
• Appearance is an outward expression of quality of the product and is the first
communication of the product with the user.
• For any product, there exists a relationship between the functional requirement and
the appearance of a product.
Aesthetic Considerations
25. • The aesthetic quality contributes to the performance of the product, though
the extent of contribution varies from the product to product.
• The following guidelines may be used in aesthetic design (design for
appearance):
• The appearance should contribute to the performance of the product.
For example, the aerodynamic shape of the car will have a lesser air
resistance, resulting in the lesser fuel consumption.
• The appearance should reflect the function of the product.
For example, the aerodynamic shape of the car indicates the speed.
• The appearance should reflect the quality of the product.
For example, the robust and heavy appearance of the hydraulic press reflects its
strength and rigidity
Aesthetic Considerations
26. • The appearance should not be at too much of extra cost unless it is a prime
requirement.
• The appearance should be suitable to the environment in which the product is
used.
• The growing importance of the aesthetic considerations in product design has
given rise to a separate disciple known as industrial design.
• The job of an industrial designer is to create new shapes and forms for the
product which are aesthetically appealing
– Form (Shape)
There are five basic forms of the products, namely, step, taper, shear, streamline and sculpture
Aesthetic Considerations
27. Step form:
The step form is a stepped structure having vertical accent
It is similar to the shape of a multistorey building.
Taper form
The taper form consists of tapered blocks or tapered cylinders.
Shear form
The shear form has a square outlook.
Streamline form
The streamline form has a streamlined shape having a smooth flow as seen in automobile and
aeroplane structures
Sculpture form
Aesthetic Considerations
28. Aesthetic Considerations
The sculpture and stream forms are suitable for mobile products like vehicles, while step
and shear forms are suitable for stationary products
29. • Colour
Colour is one of the major contributors to the aesthetic appeal of the product.
Many colours are linked with different moods and conditions.
The selection of the colour should be compatible with the conventions.
Morgan has suggested the colour code given in the following Table.
Aesthetic Considerations
Colour Meaning
Red Danger, Hazard, Hot
Orange Possible Danger
Yellow Caution
Green Safety
Blue Caution-Cold
Grey Dull
30. • Material and Surface Finish
The material and surface finish of the product contribute significantly to
the appearance.
The material like, stainless steel gives better appearance than the cast irons,
plain carbon steels or low alloy steels.
The brass or bronze give richness to the appearance of the product.
The products with better surface finish are always aesthetically pleasing.
The surface coating processes like: spray painting, anodizing, electroplating,
etc. greatly enhances the aesthetic appeal of the product.
Aesthetic Considerations
31. • Ergonomics is defined as the scientific study of the man-machine-working
environment relationship and the application of anatomical, physiological
and psychological principles to solve the problems arising from this
relationship
• The word ergonomic is formed from two Greek word: ergo means work and
nomic mean natural laws.
• The final objective of the ergonomics is to make the machine fit for user rather
than to make the user adapt himself or herself to the machine.
• It aims at decreasing the physical and mental stresses to the user.
• Psychology - Experimental psychologists who study people at work to provide
data on such things as: Human sensory capacities, psychomotor
performance, Human decision making, Human error rates, Selection tests and
procedures, Learning and training.
Ergonomic Considerations
32. • Anthropometry - An applied branch of anthropology concerned with the
measurement of the physical features of people. Measures how tall we are,
how far we can reach, how wide our hips are, how our joints flex, and how
our bodies move.
• Applied Physiology - Concerns the vital processes such as cardiac function,
respiration, oxygen consumption, and electromyography activity, and the
responses of these vital processes to work, stress, and environmental
influences.
Ergonomic Considerations
34. Ergonomic Considerations
• This man-machine closed loop system in influenced by the working environmental
factors such as: lighting, noise, temperature, humidity, air circulation, etc.
• Ergonomic Considerations in Design of Displays
• Ergonomic Considerations in Design of Controls
• Working Environment.
• Lighting
• Noise
• Temperature
• Humidity and air circulation
35. Design for Manufacturing and Assembly
(DFMA)
• Design for manufacturing and assembly are simple guidelines
formulated to get the below benefits
• It simplifies the design
• It simplifies the production processes and decreases the product cost
• It improves product quality and reliability (because if the production
process is simplified, then there is less opportunity for errors).
• It decreases the assembly cost.
• It decreases the assembly time.
• It reduces time required to bring a new product into market.
36. Design for Manufacturing and Assembly
(DFMA)
• Design for Assembly or DFA Guidelines (Assembly Considerations in Design)
– Reduce the Part Counts
– Design engineers should try for product design that uses the minimum number
of parts
– Fewer parts result in lower costs
– It also makes assembly simpler and fewer chances of defects.
37. Design for Manufacturing and Assembly
(DFMA)
• Design for Assembly or DFA Guidelines (Assembly Considerations in Design)
– Use modular designs:
– Modularize multiple parts into single sub-assemblies
– Modular design reduces the number of parts being assembled at any
one time and also simplifies final assembly
– Field service becomes simple, fast and cheap because dismantling is
faster and requires fewer tools.
•
38. Design for Manufacturing and Assembly
(DFMA)
• Design for Assembly or DFA Guidelines (Assembly Considerations in Design)
• Assemble in the open
• Design to allow assembly in open spaces, not confined spaces
• Assembly operation should be carried out in clear view. This is
important in manual assembly
•
39. Design for Manufacturing and Assembly
(DFMA)
• Design for Assembly or DFA Guidelines (Assembly Considerations in Design)
• Design parts for simple assembly:
• Design parts with orienting features to make alignment easier
•
40. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Why casting????
• Complex parts which are difficult to machine, are made by the casting
process
• Almost any metal can be melted and cast. Most of the sand cast parts
are made of cast iron, aluminum alloys and brass
• The size of the sand casting can be as small as 10 g and as large as 200
x 103 kg
• Sand castings have irregular and grainy surfaces and machining is
required if the part is moving with respect to some other part or
structure
41. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Why casting????
• Cast components are stable, rigid and strong compared with
machined or forged parts.
• Typical examples of cast components are machine tool beds
and structures, cylinder blocks of internal combustion engines,
pumps and gear box housings.
42. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Basic considerations of casting
• Always keep the stressed areas of the parts in compression
• Round all external corners
• Wherever possible, the section thickness throughout should be held
as uniform as compatible with overall design considerations
• Avoid concentration of metal at the junctions
• Avoid very thin sections
• The wall adjacent to the drilled hole should have a thickness
equivalent to the thickness of the main body
43. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Basic considerations of casting
• Oval-shaped holes are preferred with larger dimensions along the
direction of forces
• To facilitate easy removal, the pattern must have some draft
• Outside bosses should be omitted to facilitate a straight pattern
draft
44. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Always keep the stressed areas of the parts in compression
• Cast iron has more compressive strength than its tensile strength
• The castings should be placed in such a way that they are
subjected to compressive rather than tensile stresses.
•
(a) Incorrect (Part in tension) (b) Correct (Part in compression)
45. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Always keep the stressed areas of the parts in compression
• When tensile stresses are unavoidable, a clamping device such as
a tie rod or a bearing cap should be considered.
• The clamping device relieves the cast iron components from tensile
stresses
46. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Round all external corners
• It increases the endurance limit of the component and reduces the
formation of brittle chilled edges
• When the metal in the corner cools faster than the metal adjacent
to the corner, brittle chilled edges are formed
• Appropriate fillet radius reduces the stress concentration
47. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Wherever possible, the section thickness throughout should be held as
uniform as compatible with overall design considerations
• Abrupt changes in the cross-section result in high stress concentration
• If the thickness is to be varied at all, the change should be gradual
48. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Avoid concentration of metal at the junctions
• At the junction, there is a concentration of metal.
• Even after the metal on the surface solidifies, the central portion still
remains in the molten stage, with the result that a shrinkage cavity or
blowhole may appear at the center
• There are two ways to avoid the concentration of metal.
• One is to provide a cored opening in webs and ribs
• Alternatively, one can stagger the ribs and webs
49. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Avoid concentration of metal at the junctions
Cored Holes Staggered ribs
50. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Avoid very thin sections
• It depends upon the process of casting such as sand casting ,
permanent mold casting or die casting
– The wall adjacent to the drilled hole should have a thickness equivalent to the
thickness of the main body
• The inserted stud will not restore the strength of the original thickness.
•
51. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Oval-shaped holes are preferred with larger dimensions along the
direction of forces
52. Design for Manufacturing and Assembly
(DFMA)
• Design of components for casting
• Outside bosses should be omitted to facilitate a straight pattern draft
53. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Forging
• Why forging????
• A properly designed forging is not only sound with regard to strength but it also
helps reduce the forging forces, improves die life and simplifies die design
• Forged components are usually made of steels and non-ferrous metals.
• They can be as small as a gudgeon pin and as large as a crankshaft.
• Forged components are used under the following circumstances:
• Moving components requiring light weight to reduce inertia forces, e.g.
connecting rod of I. C. engines, Components subjected to excessive stresses, e.g.
aircraft structures, Small components that must be supported by other structures
or parts, e.g. hand tools and handles, Components requiring pressure tightness
where the part must be free from internal cracks, e.g. valve bodies, Components
whose failure would cause injury and expensive damage are forged for safety.
54. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Forging
• Why forging????
• A properly designed forging is not only sound with regard to strength but it also
helps reduce the forging forces, improves die life and simplifies die design
• Forged components are usually made of steels and non-ferrous metals.
• They can be as small as a gudgeon pin and as large as a crankshaft.
• Forged components are used under the following circumstances:
• Moving components requiring light weight to reduce inertia forces, e.g.
connecting rod of I. C. engines, Components subjected to excessive stresses, e.g.
aircraft structures, Small components that must be supported by other structures
or parts, e.g. hand tools and handles, Components requiring pressure tightness
where the part must be free from internal cracks, e.g. valve bodies, Components
whose failure would cause injury and expensive damage are forged for safety.
55. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Forging
While designing a forging, advantage should be taken of the direction of fibre lines
• There are no fibre lines in the cast component and the grains are scattered.
• In case of a component prepared by machining methods, such as turning
or milling, the original fibre lines of rolled stock are broken.
• It is only in case of forged parts that the fibre lines are arranged in a favorable
way to withstand stresses due to external load.
• While designing a forging, the profile is selected in such a way that fibre lines
are parallel to tensile forces and perpendicular to shear forces
56. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Forging
While designing a forging, advantage should be taken of the direction of fibre lines
57. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Forging
The forged component should be provided with an adequate draft
• The draft angle is provided for an easy removal of the part from the die
impressions
58. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Forging
• The parting line should be in one plane as far as possible and it should divide the
forging into two equal parts.
• When the parting line is broken, it results in unbalanced forging forces, which tends to displace
the two die halves.
59. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Welding
• Why welding?????
• Welding is the most important method of joining the parts into a complex
assembly
• Select the Material with High Weldability
• In general, low carbon steel is more easily welded than high carbon steel.
• Higher carbon content tends to harden the welded joint, as a result of which the weld
is susceptible to cracks.
60. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Welding
• Use Minimum Number of Welds
• Only the adjoining area of the joint is heated up, which has no freedom
to expand or contract.
• Uneven expansion and contraction in this adjoining area and parent metal
results in distortion.
• Since distortion always occurs in welding, the design should involve a
minimum number of welds and avoid over welding.
• It will not only reduce the distortion but also the cost
61. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Welding
• Use Standard Components
• The designer should specify standard sizes for plates, bars and rolled sections.
• Non-standard sections involve flame cutting of plates and additional welding.
• As far as possible, the designer should select plates of equal thickness for a
butt joint.
62. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Welding
• Select Proper Location for the Weld
• The welded joint should be located in an area where stresses and deflection are not critical.
• Also, it should be located at such a place that the welder and welding machine has
unobstructed access to that location.
• Prescribe Correct Sequence of Welding
• The designer should consider the sequence in which the parts should be
welded together for minimum distortion.
• This is particularly important for a complex job involving a number of welds.
• An incorrect sequence of welding causes distortion and sometimes cracks in
the weld metal due to stress concentration at some point in fabrication
63. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Welding
• Reduce edge preparation
• It is necessary to prepare bevel edges for the components prior to
welding operation.
• This preparatory work can be totally eliminated by making a slight change in
the arrangement of components.
(a) Incorrect (b) Correct
64. Design for Manufacturing and Assembly
(DFMA)
• Design of components for Machining
• Why machining???
• Machined components are widely used in all industrial products.
• They are usually made from ferrous and non-ferrous metals.
• They are as small as a gear in a wristwatch and as large as huge turbine
housing.
• Metal-cutting operations: Turning, Milling, drilling, shaping, boring, reaming
etc.
• Surface finishing operations: Grinding, buffing etc.