BIW FIXTURES PRE - DESIGN PROCESS ( Design Methodology & Structuring a design tree )

Question No.1 - What is Design methodologies ? 

Answer:

DESIGN METHODOLOGIES:

Design methodologies is nothing but the steps followed during the concept designing stages of fixture design. The various stages of design methodologies are,

1. Purchase order.
2. Inputs from customer.
3. Percentage of completion criteria.
4. Design outputs.

                            Figure 1.  Various stages of Design methodologies

1. Purchase order:

• A purchase order (PO) is a commercial document and first official offer issued by a buyer to a seller indicating types, quantities, and agreed prices for products or services. It is used to control the purchasing of products and services from external suppliers. Purchase orders can be an essential part of Entreprise Resource Planning system orders.
• Purchase order is a order from customer for start of the work.
• After offer has been finalized customer will be releasing the LOI/PO (Purchase order).
• Once PO is released we have to start the work.
• After PO from the customer we have to prepare the schedule.
• Purchase order is the confirmation document from customer to proceed the comitted work for them. 

2. Inputs from customer:

The inputs from the customers are as below,

1. Functional requirements: The purpose or the function of the fixture will be given as inputs from the customers like what are the process the fixture is going to do i.e welding,gluing,riveting or whether it is a checking fixture,etc.
2. Preferred standars: As we know different companies follow different standards, we will be following the standards followed by the customers. By following standards the time of designing and manufacturing of parts will be saved, which will be automatically minimizing the time of the projects. As for the standard parts, it can be easily replaced from the used fixture to the new fixture. Which reduce the cost.
3. Car products: The inputs we get from car products are GD&T, part list, Cad files of car part, clamp plan, Product assembly process sheet.
4. Layout: Layout shows the entire assembly plan to understand the process. Layout provides the information of flow of parts, station pitch, robot stations, Accessories like tool changers & tip dressers,sub assembly links, plat form height, loading/unloading sequence/height.
5. Ergo Data: As same as prfered standards, different companies follow different standards of Ergo data. We have to follow the customer standards of Ergo data. The inputs of Ergo data will given by the customer mostly in case of manually operated fixtures/manual fixtures. The Ergo data is mainly used to make the operator comfortable which may leads to improve the efficiency in cycle time & production. Ergo data provides inputs like Platform height, maximum & minimum reach from operator to fixture, maximum & minimum height of the fixture, whether the child parts/ assemblies are visible while clamping or loading & unloading. Also provides informations like Loading height, working safety zone of operator, etc.
6. Weld study: Weld study is the important inputs given by the customer.It gives details about the study of particular gun that we use for welding. Also the datas like No. of weld, position of weld in the components will be given.  In short, weld study includes weld gun details, weld matrix & weld points. 
7. Standard detailing Templates: This inputs include the detailing templates of 2D cad drawing as per the customer standards.So we have to follow the detailing templates as per the customer standards.  

3. Percentage of completion criteria:

• It is followed in the designing stages & dispatch stages of welding fixtures.
• It hepls to track or identify how much task completed & how much to go further for completing a fixture.
• Input & concept design - 0 - 25%
• Concept approval & simulation check - 25 - 40%
• Design freezing & detailing - 40 - 85%
• check & final dispatch - 85 -100%
• The above mentioned percenatge are the percentages of stage wise completion criteria of the projects.

4. Design output:

• The output is 3D models & the 2D drawings of the tools.
• Which includes keysheets & layout sheets for unitized tool whereas no need of keysheets for non unitized tool.

Hence, the design methodologies are explained in detail.

 

Question No.2 - What are the inputs required from the customer to start designing a fixture ?

Answer:

THE INPUTS REQUIRED FROM THE CUSTOMER TO START DESIGNING A FIXTURE:

The inputs required from the customer to start designing a fixture are as follows,

1. Functional requirements.
2. Preferred standard components.
3. Car products.
4. Layout.
5. Ergo - data.
6. Weld study.
7. Standard detailing templates.

A. Functional Requirements:

• The purpose or the function of the fixture will be given as inputs from the customers like what are the process the fixture is going to do i.e welding(Spot or seam weld),gluing,riveting,hemming or whether it is a checking fixture or a storage racks etc.
• It is one of the basic requirements to get from the customer to start designing a fixture.

B. Preferred standard components:

• As we know different companies follow different standards, we will be following the standards followed by the customers.
• By following standards the time of designing and manufacturing of parts will be saved, which will be automatically minimizing the time of the projects.
• As for the standard parts, it can be easily replaced from the used fixture to the new fixture. Which reduce the cost.
• Some of the preferred standard components used in BIW fixtures are given below,

1. Standards like ABB, NAAMS, DESTACO, ZYTRAN, TUNKERS are used in design & manufacturing of fixtures.
2. Standard Parts like Risers, L-blocks, Retainers, pins, NC blocks, shims, etc.
3. Components like clamps, cylinders, slides, switches, sensors, etc.
4.  Weld guns, Tip dressers, Tool changers, etc. Tip dressers are to sharpen the tip of the tools whereas Tool changers are used in robots to do various process. As robots are too costly, tool changers are used.

Below I have explained some of the standards in detail 

ABB - It is a Robots manufacturing company.

some example of description of standard robots are, Robust IRB 7600 robots, which can , hold the panels securely and accurately in place while IRB 6640 robots perform the welding.

The below picture shows the welding line is installed at Great Wall Motors’ (GWM) recently opened and internationally acclaimed automotive plant in Tianjin, China.One of the factory’s most highly publicized and productive manufacturing lines is the ABB welding line, which comprises among other things a fleet of ABB robots and patented ABB framing and hemming technologies.

Figure 1. The welding line comprises of ABB robots installed at Great Wall Motors (GWM),China.

NAAMS stands for North American Automotive Metric Standard.

Automotive manufacturers such as Chrysler, Ford and General Motors and suppliers such as Dayton Progress, Lamina, Danly IEM, and Sankyo Oilless Industry USA became participants in the initiatives.  They were the reason NAAMS is in metric dimensions, it was the unit of measurement they all adopted. The standards started gaining momentum in North America but Europe was hesitant to adopt the name.  Therefore, the official name became what it is today: NAAMS Global Standard Components – Stamping and NAAMS Global Standard Components – Assembly.

Some NAAMS Standard components are Bases, Fastener components, power clamp, L - Block component, Rough locator pins, Shims & spacer components, NC blocks, pivot index, Modular welding guns, cylinders & shock components, rest blocks, etc.

                                 Figure 2. NAAMS catalogue

We can also import some of the Cad files in 3D/2D from online NAAMS catlog. The below picture shows the Dwg. file of standard Base ASB 1212 - 1200X1200 which I found from online catalogue

     Figure 3. NAAMS - Standard base (Base ASB 1212)

Many of these NAAMS parts can even be used outside of the automotive industry.  The NAAMS initiative has become a way of life for many engineers.  Perhaps it can be found that designers in the automotive industry that venture into different industries can utilize these parts to match their design needs.  Design engineering can require a lot of creativity.  Engineers find themselves constantly thinking outside the box and with the NAAMS initiative engineer’s can certainly expand their horizons.

                   Figure 4. NC Block index & Shims index

We can get the NAAMS standard codes from the required part index.

The catalogue will contain drawings with standard dimensions. As per our requirements we should choose the standard parts/components by refering the standard dimensions mentioned in the catalogue. Also the standards will be useful for assembling the components easily without any offsets.

Below picture shows the standard dimensions for power clamp arm (60 series).

Figure 5. Power clamp arm 60 Series

Figure 6. NAAMS Standards of Metric fiiting Shims (1-slot)

DESTACO - It is a Dover corporation company. DESTACO is a manufacturers of workholding devices like manual clamps, Pneumatic clamps, grippers, conveyors, automatic tool changers, end effector toolings, etc.

The below picture shows, some of the products of DESTACO.

 Figure 7. Manual clamping, Pneumatic & Power clamping system of DESTACO

                               Figure 8. Grippers of DESTACO 

            Figure 9. Robot toolings of DESTACO

ZYTRAN - Zytran automation is a Gripper manufacturer. Grippers by ZAYTRAN are universally applicable "out-of-the-box". The use of third-generation ZAYTRAN technology and the selection of super tough, corrosive resistant materials allow these products to efficiently serve day-to-day as well as tough, nearly impossible long stroke gripper applications BUT are priced competitively with commodity products! ZAYTRAN gripper technology provides precision in extreme environments such as clean rooms, grinder loading, automotive, and die casting.

ZAYTRAN's patented helix synchronization system facilitates extremely long strokes.  In addition, wear is minimized because the force and synchronization systems are independent.  

As per the size and specifications, some of the ZYTRAN product grippers are,

• Grippers for "normal" size jobs and clean rooms - MAGNUM Grippers
• The GPL and GPAL mid to large grippers take our classic design and make them lighter with more force. - GPAL Grippera.
• For really big gripper jobs, 500 pounds (2200N) of force per jaw, strokes to 350mm - X RAY -S Long stroke Grippers.

Some of the Applications of ZYTRAN Grippers are shown below including pictures.They are,

                         Figure 10. Some of the applicaton of ZYTRAN Grippers

TUNKERS -  TUNKERS are the manufacturer of Automation products,grippers, Robotic weldings & clamping technology. Clamps manufactured by TÜNKERS stand out due to universal applicability and distinguishing construction features. The extensive product range comprises pneumatic, hydraulic, electric and manual clamping systems.

Some of the products of TUNKERS are shown in below picture.

                                 Figure 11. Some of the Products of TUNKERS

C. Car Products: The inputs we get from car products are: GD&T, part list, Cad files of car part, clamp plan, Product assembly process sheet.

1. GD&T: It provides information of locating pins, Rest, clamp, Damp & slide unit informaton of each station. Also includes the information of sequence of openings of clamps, dumps & slide stroke information.
2. Part lists: It gives the lists of parts which are going to assembled in the fixture. The list contains the informtion of Part number, part name, Revision of fixture, part thickness, etc.
3. Clamp plan: Clamp plan provides the informtion of location of pins, Rest units, clamp unit, Dumps etc. It is the important input from customer. The clamp plan/position should not be changed without the knowledge of customers.
4. 3D Cad file: The 3D model of the car part will be given from customer. From that 3D model we will be developing our fixture design process. The 3D cad file will be in the format of Step file (stp.) or IGES file ( igs.)
5. Product assembly process sheet: It gives the information of stage wise assembly process like how the parts move from one assembly station to other after the completion of joining process.

D. Layouts:

• Layout shows the entire assembly plan to understand the process.
• Layout provides the information of flow of parts, station pitch, robot stations, Accessories like tool changers & tip dressers,sub assembly links, plat form height, loading/unloading sequence/height.

                                Figure 12. Layout 

E. Ergo Data:

• As same as prfered standards, different companies follow different standards of Ergo data.
• We have to follow the customer standards of Ergo data.
• The inputs of Ergo data will given by the customer mostly in case of manually operated fixtures/manual fixtures.
• The Ergo data is mainly used to make the operator comfortable which may leads to improve the efficiency in cycle time & production.  

         Figure 13. Ergonomics in Fixtures

• Ergo data provides inputs like Platform height, maximum & minimum reach from operator to fixture, maximum & minimum height of the fixture, whether the child parts/ assemblies are visible while clamping or loading & unloading.
• Also provides informations like Loading height, working safety zone of operator, etc.

F. Weld Study:

• Weld study is the important inputs given by the customer.It gives details about the study of particular gun that we use for welding.
• Also the datas like No. of weld, position of weld in the components will be given. 
• In short, weld study includes weld gun details, weld matrix & weld points. 
• Generally weld points will be given in spheres.

• 

         Figure 14. Weld study (As it shows the red sphere, it is Geo weld points)

G. Standard detailing templates:

• This inputs include the detailing templates of 2D cad drawing as per the customer standards.
• So we have to follow the detailing templates as per the customer standards.  

     

              Figure 15. Standard detailing templates

Hence, the inputs required from the customer to start designing a fixture are explained in detail.

 

Question No. 3 - What is the inputs we get from car products ?

Answer:

INPUTS WE GET FROM CAR PRODUCTS: 

Inputs we get from car products includes,

1. GD&T.
2. Part lists.
3. 3D cad file.
4. Clamp plan.
5. Product assembly process sheet.

i. GD&T:

• GD&T -Geometric Dimensioning & Tolerance.
•  It provides information of locating pins, Rest, clamp, Damp & slide unit informaton of each station.
• Also includes the information of sequence of openings of clamps, dumps & slide stroke information.

                    Figure 1. GD&T inputs from car products

         Figure 2. Functional dimension requirement on the assembly

Some examples related to the inputs we get from the GD&T in the car products are shown below,

Surface Profile Tolerances:

A surface profile tolerance zone is a three-dimensional volume establishing permissible boundaries of feature(s) of a part. A surface profile tolerance can be used to define a tolerance zone to control combinations of size, form, orientation and location of a feature relative to true profile.  For additional information about profile tolerances, please refer to the section 8 of the ASME Y14.5-2009 standard . In Figure 3, we can observe the car door part located through datum targets with surface profile tolerances. In the next sections, we shall analyze these tolerances further to better understand their functions.

Surface Profile Tolerance along the Left Side of the Door:

As shown in Figure 4, the surface profile tolerance zone between points P and R (along the left side of the door) must lie with the profile boundaries 1 mm apart (defined by the red zone) and equally disposed about the true profile (0.5 mm on each side). Thus, the feature must be located within the tolerance zone of 1 mm, relative to the datum reference frame ABC.  In Detail View, we can observe the actual profile of the door (in dark blue) staying within these boundaries.

Surface Profile Tolerance along the Top and Bottom Sides of the Door:

Surface profile tolerance zones on other edges of the door follow the same logic applied above.

As shown in Figure 5, the surface profile tolerance zone between points P and O (along the top side of the door) must lie with the profile boundaries 0.5 mm apart (defined by the red zone) and equally disposed about the true profile (0.25 mm on each side).

Lastly, in Figure 6, the surface profile tolerance zone between points R and S (along the bottom side of the door) must lie with the profile boundaries 0.5 mm apart (defined by the red zone) and equally disposed about the true profile (0.25 mm on each side).

ii. Part lists:

• It gives the lists of parts which are going to assembled in the fixture.
• The list contains the informtion of Part number, part name, Revision of fixture, part thickness, etc.

               Figure 7. Example of Part lists

iii. 3D cad files:

• The 3D model of the car part will be given from customer. From that 3D model we will be developing our fixture design process.
• The 3D cad file will be in the format of Step file (stp.) or IGES file ( igs.) or sometimes it may be in part file (prt.).

                 Figure 8. 3D cad model 

iv. Clamp plan: 

• Clamp plan provides the informtion of location of pins, Rest units, clamp unit, Dumps etc.
• It is the important input from customer. The clamp plan/position should not be changed without the knowledge of customers.
• It gives the detail of the exact position of the clamping units.

v. Product assembly process sheet:

• It gives the information of stage wise assembly process like how the parts move from one assembly station to other after the completion of joining process.
• It shows the sequence of operations/ process to be done in a part or a panel.
• Also what are the parts to be joined with the panel will shown in sequence.
• From this sheet we can trace out the pending process which has to further go on for completion of part.
• From this product assembly process sheet designer can understand the sequence for designing the fixtures.

 

        Figure 9. Process assembly process sheet

Hence, the inputs we get from car products are explained in detail.

 

Question No.4 - What is the clamp plan ?

Answer:

CLAMP:

A clamp is a fastening device used to hold or secure objects tightly together to prevent movement or separation through the application of inward pressure.

Essential requirements of clamps:

All clamps must fulfill four essential  requirements. They are,

1. The workpiece must be held rigid while undergoing operations.
2. The time required for loading/unloading  the tool must be as short as possible, which means the clamping device must be quick acting.
3. When subjected to vibration, chattered, heavy pressure the clamping must be positive.
4. The clamp must not damage the workpiece.

CLAMP PLAN:

• Clamp plan provides the informtion of location of pins, Rest units, clamp unit, Dumps etc.
• It is the important input from customer. The clamp plan/position should not be changed without the knowledge of customers.
• It gives the detail of the exact position of the clamping units by mentioning a co ordinates in the particular position.

                                       Figure 1. Clamp plan

Hence, the clamp plan is expalined in detail.

 

Question No.4 -What is the purpose of the Layout ? 

Answer:

THE PURPOSE OF THE LAYOUT:

• The purpose of the layout is to understand the information about where the fixtures & robots are been placed, working area covered by the robot, what are the fixtures assigned for the robots to do the process, etc.
• Layout shows the entire assembly plan to understand the process.

                                                                         Figure 1. Layout

• The circle around the robot is the swept area of the particular robot which shows the reachability of the robots particularly with the confine circle.
• Layout provides the information of flow of parts, station pitch, robot stations, Accessories like tool changers & tip dressers,sub assembly links, plat form height, loading/unloading sequence/height.
• Flow of parts: It shows the flow of the parts/panel in the assembly line or shop floor like how component move from one station to other station after the completion of process .
• Station pitch: The distance between two stations is known as station pitch. It shows the space constaints between the two stations, which shows in layot.
• Robot stations: It shows the position where the robots & their accessories placed, which is shown in the layout. 
• Sub assembly link: Sub assembly link is nothing but the links between the assembly fixtures & the main assembly line. It shows that how the sub assemblyfixtures are linked with the main assembly line. 
• The main purpose of the layout is to understand the entire plan of the assembly line.
• The layout providing the above informations like flow of parts, station pitch, robot stations, etc used to understand the working process of robots, what are the fixtures assigned for  the robots, space constraint,etc.
• By considering the layout, the designers can develop the concept sketches of fixtures without any clash in the assembly lines.
• One of the main purpose is we get information about the space constraint which helps to develop the robotic cell without any clash during working.

Hence, the purpose of the layout is explained in detail.

 

Question No.6 - What is Ergo-data ?

Answer:

ERGO DATA:

Ergo data is nothing but the data or inputs which gives the human factors engineering data, between the operator & his working environment. Before detailing about ergo data we should know about ergonomics in detail.

ERGONOMICS:

Ergonomics also knon as human engineering & human factors engineering is the scientific study of the relationship between man and his working environments.

OBJECTIVES OF ERGONOMICS:

• The fundamental objective of the study of ergonomics is to optimize the integration of man & machine so as to improve the productivity & accuracy.
• In short, the objective of ergonomics is designing for human use & optimizing working & living condition.
• Two broader objectives of ergonomics are :

1. To enhance the efficiency and effectiveness with which the work is carried out so as to increase the convenience of use, reduced errors & increase in productivity.
2. To enhance certain desirable human values including safety, reduced stress & fatigue, and improved quality of life.

Ergonomics involves the design of:  

1. A work place suitable for the worker.
2. Machinery & controls, so as to minimize physical strain on the worker to enable the improvement in the efficiency.
3. A environment for performing a task most effectively and conducive.
4. A conducive task & work organization.

            Figure 1. Shows how Ergonomic design made people to work done ease with comfort.

Benifits of Ergonomics:

• Improved working condition.
• Reduce physical workload.
• Improved work postures.
• Reduced efforts of certain movements.
• Better reading instrument displays, handling of machine levers & controls.
• Reduced unnecessary information recall efforts.

Below, I have given a basic example of ergonomics in the workstation

Figure 2. Example of Ergonomics in Workstations

ERGO DATA:

• Ergo data is nothing but the data or inputs which gives the human factors engineering data, between the operator & his working environment.
• Ergo data is mostly needed while there is a need of manual operator/operation.
• Ergo data will be given from customer as per their standard.Every customers follow different ergodata standards.
• As per customer standards, we have to consider the ergonomics in the fixture while designing.
• From ergo data we get the details or inputs realated between the operator and his working fixture.
• The Ergo data is mainly used to make the operator comfortable which may leads to improve the efficiency in cycle time & production.  

         Figure 3. Ergonomics in Fixtures

As shown in the below figure 4. While loading & unloading the panels the approach of the operator from the fixture should be made easy in manual fixtures.

Ergo data gives such inputs to consider while designing the fixture 

       Figure 4. shows the easy approach for the operator.

• While loading & unloading the panels the approach of the operator from the fixture should be made easy in manual fixtures.Ergo data gives such inputs to consider while designing the fixture 

• Ergo data provides inputs like Platform height, maximum & minimum reach from operator to fixture, maximum & minimum height of the fixture, whether the child parts/ assemblies are visible while clamping or loading & unloading.

• Also provides informations like Loading height, working safety zone of operator, etc.

• Mainly the ergodata is to make the operator comfortable like Visual check of the part, too much of bending may get back bone pain or shoulder sprain for operator which may tends to consume time & affect the efficiency of production.

• Ergodata is also needed to make the operator more efficient & timing saving. Also helpful to improve productivity.

             Figure 5. The Inputs given in the Ergo data 

Hence, the Ergodata are explained in detail.

 

Question No.7 - What do you understand by weld study ?

Answer:

WELD STUDY:

• Weld study is the important inputs from the customer.
• It gives the study of particular gun that we use for weld, No. of spots to be welded, Sequenece of weld, position of weld in the components.
• In short, Weld study includes weld gun details, weld matrix & weld points.
• Generally the weld points will be given in spheres.
• Red Sphere represents the Geo spot weld points whereas Green sphere represents the Respot weld points
• The weld points are classified as,

1. Geo weld points.
2. Respot weld points.

a. Geo weld points:

• The Geo weld points are which is planned in the Geo fixture. 
• These weld will determine the postion of the panels as per the given data in drawing.
• The Geo weld points are represent in red spheres in the weld study inputs given by the customers.

b. Respot weld points:

• The Respot weld points are planned in the Respot tool.
• These weld will determine the strength/stiffness of the panel/components.
• The Respot weld points are represent in green spheres in the weld study inputs given by the customers.

       Figure 1. Weld study (As it shows the red sphere, it is Geo weld points)

Hence, the weld study is explained and understand.

 

Question No.8 - What are the criteria for percentage completion in the designing stage ? Explain in detail.

Answer:

THE CRITERIA FOR PERCENTAGE COMPLETION IN THE DESIGNING  STAGE:

• The percentage completion criteria is followed in the designing stages & dispatch stages of welding fixtures.
• This percentage completion criteria is followed to trace the project whether it matches the commited date given to the customer for handovering the projects to them.
• Also it helps us to identify the stages in the projects like how much the project is completed and what are the further stages are in pending to complete which helps us to complete the project on the commited time and date.
• The percentage completion criteria is divided into four stages to identify the percentage of the completion of work.
• The four stages of percentage completion criteria are as follows,

1. Input & concept design.
2. Concet approval & simulation check.
3. Design freezing & detailing.
4. Check & final dispatch.

1. Input & concet design:

• If the project is in the stage of Input & concept design then the percentage completion criteria of the project will be between 0 - 25%
• After the completion of input & concept design then the project will be moved to concept approval & simulation check which is the second stage in percentage completion criteria.

2. Concept approval & simulation check:

• If the project is in the stage of Concept approval & Simulation check then the percentage completion criteria of the project will be between 25% - 40%
• After the completion of concept approval & simulation check then the project will be moved to Design freezing & detailing which is the third stage in percentage completion criteria.

3. Design freezing & detailing:

• If the project is in the stage of Design freezing & detailing then the percentage completion criteria of the project will be between 40% - 85%
• After the completion of design freezing & detailing then the project will be moved to check & final dispatch which the fourth & the last stage in percentage completion criteria.

4. Check & final dispatch:

• If the project is in the stage of Check & final dispatch then the percentage completion criteria of the project will be between 85% - 100%
• After the check the project will be finally dispatched successfully to the customer.

Hence, the criteria for percentage completion in the designing stage is explained in detail.

 

Question No.9 - Brief about output in design.

Answer:

OUTPUT IN DESIGN:

• The output is 3D models & the 2D drawings of of the toos.
• For unitized tools (multiple unit in a common base) requires two types of drawing sheets.
• Example of unitized tool: A tool with multiple units like rest unit, clamp unit, fixed pin unit, rectractable pin unit, rough locator unit, sensor unit, etc. in a common base
• The two types of drawing sheets are,

1. key sheet.
2. Layout sheet.

a. Key sheet:

• Key sheet gives or shows the index of units & their placements on the tool base.
• It will have an orthogonal view of the fixture including a numbered balloon drawing mentioning the units.

          Figure 1. Key sheet

b. Layout sheet:

• Layout sheet shows a detail drawing of individual units to include all of their components.
• For Nonunitized tool no need of keysheets. As they can stand alone, the drawing can be detailed completely on a layout sheets.

             Figure 2. Layout sheet

THE DESIGN OUTPUT SHOULD COMPILE FOLLOWING POINTS:

1. Approved standard components are to be used wherever possible.
2. Design must be as simple & economical as possible.
3. Design must comply with all current safety & ergonomic requirements.
4. Design must provide for controlled & damage free handling of product.
5. Adequate error proofing provision must be incorporated into each design by providing proximity switches, rough locators, etc.
6. The weight of the moving parts must be kept to a minimum while maintaining maximum strength.
7. Frames & structures are to be simple & sturdy.
8. Design clearance & accessibility for routine maintanance & service.
9. Motion control must be considered on any moving equipments.
10. Designer is responsible to validate clamps & weld guns.

Hence, the output in design are briefed.

 

Question No.10 - What do you understand by structuring a design tree ? How does it reduce errors during the design process ?

Answer:

STRUCTURING A DESIGN TREE:

• Structuring a design tree implies to a process where all the assemblies & parts are named in a specific standard. Different customers have different set of standards to structure a design tree.
• It is an important process which helps us to identify a specific part or assembly as to which project, tool/unit, it belongs to.
• This helps us to avoid the errors during design study, manufacturing, assembly, inspection, etc.
• If the parts or assembliies are not named properly or the design tree is not structured properly, it will create confusion to understand the design & may create major possibilities of making an error.
• Naming of a fixture or a unit or a part, gives the information as to which project or zone or assembly do they belong.
• It can help us to identify the quantity of items of same types or different types that are being used in the assembly.
• While start designing a fixture, the first unit will be the base unit.
• In structure tree all the manufacturing parts should be first and the standard parts should be at the last.
• Structure tree helps to study or understand the parts in the assemblies easily.

               

                      Figure 1. Design tree structure (Showing the sequence of naming procedure of assembly)

Steps to structuring a design tree:

• Step 1: Create new ----> Product ----> click OK (by clicking ok now you will enter into a product window)
• Step 2: Then right click product in a structure tree ----> go to properties ----> Rename in part number (As we created a product we have to mention the total assembly name of the fixture) ----> Click OK

The naming of the assemblies / parts / units have certain standard procedures, which I have clearly explained below.

The product name is title of the fixture. The renamed titled should be ----> P001_ZO3_ST09_00_00_R

P001 - represent the project name.

Z03 - Zone name

Pannel name will also be mentioned in some case.

ST 09 - Station name / J03 - Jig name will be mention sometimes.

00 - unit name.

00 - Part number.

R/L - is representing the Right hand side / left hand side of the panel.

The other renamed title explained in video is H1L_19A_RRFRA_JG3_00_00_R.

H1L_19A - Project name.

RRFRA - panel name.

JG3 - Jig name/number.

00 - unit name.

00 - part number.

R - indicates right side.

Thus this is how the assemblies has to be mentioned in a sequence of procedure

• Step 3: Insert ----> new component (under project title) ----> Click the newly created component and rename it as we done in the before step.

Example:  P00_ZO3_ST09_01_00_Base unit (Always the first unit should be a base unit in the structure design tree)

P00_Z03_ST09_02_00_clamp unit

01/02 - represent unit

00 - represent part

• Step 4: Repeat the same we did in before steps to create a various units like clamp unit, rest unit, etc. by creating new component.
• Step 5: Insert parts (under the particular unit name) to add parts which consists in the units. And rename the parts as we done usually in before steps.

Example: P00_Z03-ST09_02_01_Clamping mylars

P00_Z03-ST09_02_02_Clamp Arms.

Here, 01 - represents part01 (clamp mylars) in unit 02 (claming unit) whereas 02 - represents part02 (clamp arm) in unit 02 (claming unit)

           Figure 2 . Design tree structure (Showing some of the parts under the clamp unit)

• Step 6: To sketch a part in a selected unit ---> Click a part name in a structure tree (which part is to be designed) & then go to New part window. Now the part window in the selected part name on the structure tree will open. Then by selecting the sketch and various tool we can design a particular part in the units.
• Step 7: The step 6 has to be repeated for creating all parts under different units.
• Step 8: The standard parts should be mentioned at the last / mentioned after all the in house manufacturing parts in a design structure tree.
• These are the simple  steps to be followed to structuring a design tree.

  Figure 3. Design tree structure (Showing procedure of postioning the manufacturing & standard parts in a design tree)

Hence, structuring a design tree is explained in detail with the points how it reduce errors during the design process.