200+ Mechanical Engg. Design Interview Questions and Answers

Symbols used in GD&T include position, concentricity, perpendicularity, etc.

• Position symbol: Indicates the allowable deviation from the true position of a feature

• Concentricity symbol: Specifies the allowable deviation between the axis of two features

• Perpendicularity symbol: Indicates the allowable deviation from a 90-degree angle between two features

Different types of leaning techniques in machine learning

• Supervised learning

• Unsupervised learning

• Semi-supervised learning

• Reinforcement learning

• Transfer learning

• Deep learning

• Online learning

• Active learning

A robotic arm with 6 degrees of freedom for precise movements in multiple directions.

• Robotic arm with 6 degrees of freedom allows for movement in multiple directions

• Each joint of the arm provides a degree of freedom for precise control

• Commonly used in manufacturing, medical surgeries, and space exploration

Stress is the force applied to a material, while strain is the resulting deformation or change in shape.

• Stress is the internal resistance of a material to deformation under an applied force.

• Strain is the measure of deformation or change in shape of a material in response to stress.

• Stress is typically measured in units of force per unit area (such as Pascals), while strain is dimensionless.

• The relationship between stress and strain is described by the material's modulus of ela...read more

Welding symbols are graphical representations used in engineering drawings to communicate welding information.

• Welding symbols indicate the type of weld, dimensions, and other important information related to the welding process.

• They help in specifying the welding requirements without the need for lengthy written explanations.

• Common welding symbols include fillet weld, groove weld, plug weld, spot weld, etc.

• Examples of welding symbols are 'F' for fillet weld, 'V' for groove we...read more

Diesel has higher energy density than petrol, resulting in better fuel efficiency.

• Diesel has a higher energy density than petrol, meaning it can provide more energy per unit volume.

• Petrol is more volatile and burns faster than diesel.

• The capacity of diesel and petrol tanks in vehicles can vary depending on the size of the vehicle and its fuel efficiency.

• For example, a typical car may have a petrol tank capacity of around 50-70 liters, while a diesel car may have a tank capaci...read more

Yes, I have experience in creating technical documents such as design specifications, assembly instructions, and test reports.

• I have created design specifications for various projects, outlining the requirements and constraints for the design.

• I have also created assembly instructions for the manufacturing team to follow during production.

• Additionally, I have written test reports to document the results of product testing and analysis.

• I am proficient in using software such as ...read more

Rubber properties can be measured using various parameters and devices.

• Rubber properties include elasticity, tensile strength, hardness, and compression set.

• Parameters used to measure rubber properties include stress, strain, and deformation.

• Devices used to measure rubber properties include rheometers, durometers, and tensile testers.

• Rubber properties can also be measured using thermal analysis and dynamic mechanical analysis.

• Measuring rubber properties is important for ensur...read more

Heat treatment of steel involves heating and cooling to alter its properties.

• Heat treatment is used to improve the strength, hardness, and ductility of steel.

• Common heat treatment processes include annealing, quenching, and tempering.

• Annealing involves heating the steel to a specific temperature and then slowly cooling it to make it softer and more ductile.

• Quenching involves rapidly cooling the steel to increase its hardness.

• Tempering involves heating the steel to a specific ...read more

Air requirement for combustion can be calculated using stoichiometry and fuel properties.

• Determine the stoichiometric air-to-fuel ratio

• Determine the fuel properties such as heating value and molecular weight

• Calculate the mass flow rate of fuel

• Calculate the mass flow rate of air using the stoichiometric ratio

• Adjust for excess air if necessary

Understanding projection methods, GD&T symbols, and sheet metal bending concepts is crucial in mechanical design.

• First Angle Projection: Object is placed in the first quadrant; views are projected onto the plane behind the object.

• Third Angle Projection: Object is placed in the third quadrant; views are projected onto the plane in front of the object.

• GD&T Symbols: Geometric Dimensioning and Tolerancing symbols define features like flatness, circularity, and profile.

• Bend Radius...read more

Answering questions related to mechanical engineering design.

• Fit refers to the degree of tightness between two mating parts.

• IS2062 E250 is a mild steel grade with properties such as high tensile strength and good ductility.

• Drawing in first angle projection is preferred as it is more intuitive and easier to understand.

• Second and third angle projections are used in rare cases where first angle projection is not feasible.

I am proficient in various software including CAD, CAM, and simulation software.

• Proficient in CAD software such as SolidWorks, AutoCAD, and CATIA

• Experience in CAM software like Mastercam and Fusion 360

• Familiarity with simulation software such as ANSYS and COMSOL

• Proficient in programming languages like Python and MATLAB for automation and analysis

• Experience in project management software like MS Project and Asana

Distance between spot to spot and flange overlap is crucial for ensuring proper alignment and connection in mechanical engineering design.

• The distance between spot to spot refers to the spacing between two spot welds or fasteners on a joint.

• Flange overlap distance is the amount by which one flange overlaps another in a joint, ensuring proper connection and strength.

• Proper calculation of these distances is essential for structural integrity and load-bearing capacity of the des...read more

Ferrous materials contain iron while non-ferrous materials do not.

• Ferrous materials are magnetic while non-ferrous materials are not.

• Ferrous materials are prone to rust while non-ferrous materials are not.

• Examples of ferrous materials include steel and cast iron while examples of non-ferrous materials include aluminum and copper.

The minimum gap between two nested pieces of sheet depends on the thickness of the sheet and the manufacturing process.

• The gap should be at least equal to the thickness of the sheet

• The manufacturing process and material properties can affect the required gap

• Consult industry standards and guidelines for specific recommendations

• Examples: for 0.5mm sheet metal, the minimum gap should be 0.5mm; for laser cutting, the gap may need to be slightly larger to account for the heat affe...read more

Shaft basis and hole basis are two systems used to determine the tolerance limits of mating parts in mechanical design.

• Shaft basis system: The shaft is kept constant and the hole is varied to achieve the desired fit.

• Hole basis system: The hole is kept constant and the shaft is varied to achieve the desired fit.

• The system chosen depends on the application and the desired level of clearance or interference between the mating parts.

• Examples of applications include bearings, gear...read more

There are several types of beams including cantilever, simply supported, fixed, continuous, and overhanging beams.

• Cantilever beams are supported at one end and free at the other.

• Simply supported beams are supported at both ends and have no moment resistance.

• Fixed beams are supported at both ends and have moment resistance.

• Continuous beams have more than two supports and can resist bending moments.

• Overhanging beams have one or both ends extending beyond the supports.

I have extensive experience with design softwares such as AutoCAD, SolidWorks, and CATIA.

• Proficient in AutoCAD for 2D drafting and modeling

• Skilled in SolidWorks for 3D modeling and simulation

• Experience with CATIA for advanced surface modeling and assembly design

Sheet metal is a thin and flat metal material used in various industries for manufacturing components and structures.

• Sheet metal is a thin and flat metal material that can be easily bent, cut, and formed into various shapes.

• Stainless steel is a type of steel that contains chromium, which makes it resistant to corrosion and rust. It is commonly used in applications where corrosion resistance is important, such as in kitchen appliances and automotive parts.

• Mild steel, on the ot...read more

A manufacturing drawing template typically includes details such as dimensions, tolerances, materials, and finishing.

• Title block with part name, drawing number, and revision

• List of materials and their specifications

• Detailed views with dimensions and tolerances

• Bill of materials with part numbers and quantities

• Notes section for additional information

• Finishing requirements such as surface roughness and coatings

• Reference to applicable standards and specifications

Hem is added in sheetmetal design to provide strength and safety to the edges.

• Hemming is a process of folding the edge of a sheet metal to create a smooth and safe edge.

• It provides additional strength to the edge and prevents it from getting damaged or deformed.

• Hemming also improves the appearance of the sheet metal and makes it more aesthetically pleasing.

• Examples of hemming include the edges of car doors, hoods, and trunks.

• Hemming can be done using various techniques such a...read more

Yes, AutoCAD 2D hands-on experience is essential for drafting.

• AutoCAD is a widely used software for drafting in mechanical engineering.

• 2D drafting is the foundation of engineering design.

• Hands-on experience with AutoCAD 2D helps in creating accurate and efficient designs.

• It also helps in understanding the various tools and features of the software.

• Without hands-on experience, it may lead to errors and inefficiencies in the design process.

The surface roughness value of the conveyor roller depends on the application and material used.

• Surface roughness value is measured in micrometers (µm).

• The value can range from 0.1 µm to 50 µm depending on the application.

• The material used for the roller also affects the surface roughness value.

• A smoother surface reduces friction and wear on the conveyor belt.

• Surface roughness can be improved through polishing or coating.

• ISO 4287 and ISO 4288 are standards used to measure sur...read more

Yes, I have extensive experience working on AutoCAD 2D.

• I have used AutoCAD 2D for various projects in my previous job.

• I am proficient in creating and editing 2D drawings using AutoCAD.

• I am familiar with the various tools and commands in AutoCAD 2D.

• I can work on both simple and complex drawings using AutoCAD 2D.

• I am open to learning new techniques and improving my skills in AutoCAD 2D.

Constraints in design are limitations or restrictions that affect the design process and final product.

• Constraints can be related to materials, manufacturing processes, budget, time, or regulations.

• They can also be imposed by the client or end-user requirements.

• Examples of constraints include weight limitations for aerospace components, cost limitations for consumer products, and safety regulations for medical devices.

• Designers must work within these constraints to create a f...read more

To sketch mechanical components, measure with Vernier Caliper and draw freehand sketch.

• Take accurate measurements using Vernier Caliper

• Use a pencil and paper to sketch the components

• Draw the components to scale

• Label the components with their dimensions

• Check the sketch for accuracy and completeness

Shear stress of a shaft can be calculated using the formula T/J = τ/R

• Calculate torque (T) applied to the shaft

• Determine the polar moment of inertia (J) of the shaft's cross-sectional area

• Find the radius (R) of the shaft

• Use the formula T/J = τ/R to calculate the shear stress (τ) of the shaft

• Shear stress can also be calculated using the maximum shear stress formula τmax = Tc/J

• Where Tc is the torsional stress at the outer surface of the shaft

Torsion strength of a shaft can be calculated using the formula T/J=Gθ/L

• T is the torque applied to the shaft

• J is the polar moment of inertia of the shaft

• G is the shear modulus of the material of the shaft

• θ is the angle of twist

• L is the length of the shaft

• Example: For a solid circular shaft, J=πd^4/32 where d is the diameter of the shaft

Different types of metal joints include welded joints, bolted joints, riveted joints, soldered joints, and adhesive joints.

• Welded joints involve melting and fusing the metal pieces together.

• Bolted joints use bolts and nuts to secure the metal pieces together.

• Riveted joints use rivets to hold the metal pieces together.

• Soldered joints involve melting a filler metal to join the pieces together.

• Adhesive joints use adhesives to bond the metal pieces together.

Various manufacturing processes include casting, machining, welding, forming, and additive manufacturing.

• Casting: involves pouring molten metal into a mold to create a desired shape (e.g. sand casting, die casting)

• Machining: involves removing material from a workpiece using cutting tools (e.g. milling, turning)

• Welding: involves joining two or more pieces of metal together using heat and/or pressure (e.g. arc welding, spot welding)

• Forming: involves shaping a material without r...read more

Surface treatment processes are used to improve the properties of a material's surface for various applications.

• Coating: Applying a thin layer of material to the surface for protection or aesthetic purposes (e.g. painting, anodizing).

• Plating: Depositing a layer of metal onto the surface for corrosion resistance or improved appearance (e.g. electroplating, galvanizing).

• Heat treatment: Altering the material's properties through heating and cooling processes (e.g. annealing, que...read more

I am familiar with CAD softwares such as SolidWorks, AutoCAD, and CATIA.

• SolidWorks

• AutoCAD

• CATIA

Bending allowance is the amount of added length required on a sheet metal product to compensate for the material's elasticity during bending.

• Bending allowance is calculated based on the material's thickness, bend radius, and angle of bend.

• It ensures that the final product has the desired dimensions after bending.

• Bending allowance varies for different materials and bending processes.

• For example, the bending allowance for aluminum is different from that of steel.

• Bending allowan...read more

Busbar size and material are determined based on current carrying capacity, voltage drop, and mechanical strength requirements.

• Calculate the maximum current the busbar will carry

• Determine the voltage drop allowed

• Consider the mechanical strength required based on installation conditions

• Select a material with appropriate conductivity and mechanical properties

• Consult relevant standards and guidelines for busbar sizing and material selection

My design approval process approach involves thorough analysis, documentation, and collaboration with stakeholders.

• I conduct a detailed analysis of the design to ensure it meets all requirements and standards.

• I document the design process and decisions made throughout the project.

• I collaborate with stakeholders, including clients and team members, to gather feedback and ensure their needs are met.

• I conduct regular design reviews to identify and address any issues or concerns....read more

K factor is a ratio that represents the location of the neutral axis in relation to the thickness of the sheet metal.

• K factor is used in sheet metal bending to determine the amount of bending force required.

• It is a ratio of the distance from the neutral axis to the inside bend radius over the material thickness.

• Different materials and bending processes have different k factors.

• K factor affects the accuracy of the flat pattern layout and the final part dimensions.

• Typical k fac...read more

To create a thread 20x1.5 in a 2mm sheet, use a tap and die set with the appropriate size and pitch.

• Select a tap and die set with a 20x1.5 size and pitch

• Drill a hole in the 2mm sheet with a diameter slightly smaller than the tap size

• Insert the tap into the hole and turn it clockwise to create the thread

• Use the die to clean up and refine the thread

• Ensure the thread is the correct size and pitch using a thread gauge

There are three types of design process: linear, parallel, and iterative.

• Linear design process involves a step-by-step approach from concept to final product.

• Parallel design process involves multiple teams working on different aspects of the design simultaneously.

• Iterative design process involves continuous testing and refinement of the design.

• Examples of linear design process include waterfall model and V-model.

• Examples of parallel design process include concurrent engineeri...read more

I have handled a variety of projects including product design, prototyping, and testing.

• Designed and developed a new product for a client in the consumer electronics industry

• Managed the prototyping and testing phases of a medical device project

• Collaborated with a team to improve the efficiency of a manufacturing process

• Implemented design changes to improve the performance of an existing product

• Worked on a project to reduce the environmental impact of a manufacturing facility

Top down assembly is creating an assembly by starting with the top-level components and working down. Bottom up assembly is the opposite.

• Top down assembly involves starting with the highest level components and working down to the smaller parts.

• Bottom up assembly involves starting with the smaller parts and building up to the higher level components.

• Top down assembly is useful when designing complex systems with many sub-assemblies.

• Bottom up assembly is useful when designing ...read more

Sheet metal process involves designing a model on ugnx.

• Sheet metal process involves shaping and forming thin metal sheets.

• Designing on ugnx refers to using the Unigraphics NX software for creating the model.

• The model should consider factors like material thickness, bend radius, and manufacturing constraints.

• Examples of sheet metal designs include enclosures, brackets, and automotive body panels.

I am very strong in Gearbox design and have extensive experience in designing and optimizing gear systems.

• I have a deep understanding of gear geometry, materials, and manufacturing processes.

• I have designed gearboxes for various applications including automotive, aerospace, and industrial machinery.

• I am proficient in using software tools such as SolidWorks, ANSYS, and MATLAB for gearbox design and analysis.

• I have worked on projects involving gear noise reduction, efficiency i...read more

Sections in mechanical engineering design refer to the shapes of cross-sections of structural members.

• Sections can be classified as open or closed.

• Open sections have an opening or a void in the cross-section, such as a C-channel or an I-beam.

• Closed sections have a continuous cross-section, such as a rectangular or circular tube.

• Sections can also be classified based on their shape, such as square, rectangular, circular, or elliptical.

• The choice of section depends on the struct...read more

Tool test is a process to evaluate the performance of modeling tools in NX CAD.

• Tool test involves creating a test model and evaluating the accuracy and efficiency of the modeling tools.

• The test model should include a variety of features and geometries to test the capabilities of the tools.

• The test should be repeated with different tool settings and parameters to evaluate their impact on the results.

• The results of the tool test should be documented and used to inform tool sele...read more

GDT stands for Geometric Dimensioning and Tolerancing. Three common GDT call outs are concentricity, perpendicularity, and flatness.

• Concentricity: Specifies that two or more features share a common center point.

• Perpendicularity: Specifies that a surface or axis is perpendicular to a datum plane.

• Flatness: Specifies that a surface must lie within a specified flatness tolerance zone.

Heat treatment is a process of heating and cooling metals to alter their physical and mechanical properties.

• Heat treatment is used to improve the hardness, strength, toughness, and ductility of metals.

• It involves heating the metal to a specific temperature and holding it there for a certain amount of time.

• The metal is then cooled at a specific rate to achieve the desired properties.

• Common heat treatment processes include annealing, quenching, tempering, and normalizing.

• Exampl...read more