Advanced Sheet Metal Design Using NX Cad Challenge_2_Box Assembly

1. Title of the Project:

Design of Box Assembly using NX CAD 12.

2. Objective:

To design the Box Assembly as per dimensions and generate drafting using NX CAD 12.

3. Introduction:

Sheetmetal are widely used in all sectors of industries, which is due to their lighter in mass, easy manufacturability, low cost of production and product within the time constraints. Sheetmetal thickness may vary from 0.3mm to 12mm.they can be easily transformed into final model using simple pressing and bending operations CAD is a software package developed by siemens PLM software, which is widely used for designing and developing of sheet metal components.it also has various workbenches such as modelling, Analysis, drafting, Sheetmetal etc. CAD sheet metal workbench makes the design process of any sheet metal components easier.it helps in gaining design competencies of a component easily and accurately. The complex shapes of various designs can be made simpler using this software. Once the model is generated, it can also be flattened using design tools in order to get exact idea about how the actual blank may appear finally. Using this software, designers can easily judge whether the product developed is ready for manufacturability or not.

   4.Design methodology:

   

                            Methodology

     5. Description of Sketching and Modelling:

Sketching & Dimensioning:

It is an initial stage of any designing or modelling process, the outline of the geometry is created using sketch-based tools by selecting any one of the plane. Further appropriate dimensions and relations are provided for the sketch across its geometry using rapid dimensions.

Geometric Modelling:

Once the sketching and dimensioning are generated, those sketches and curves are selected for creating surfaces and solid components. features like Extrude, tab, flange, hole, were used to generate the operations on the component based on the design requirement.

Final Model:

After creating the model, the geometrical and design constraints are crosschecked across the component. If there is any changes and remodelling is needed the necessary actions were carried out as per the design requirement. Whenever the final model is satisfied using the flat pattern option, the component made to flatten to get better idea about the design.

Drafting:

Once the final model is generated and flattened, the design is dragged to the drafting workbench, where the appropriate sheet size is selected. Using base view, the various the various orientation of component is placed on the sheet with detailed information of the sheet metal component.

    6 . Steps Followed in design Process:

• Creating of geometry outline as per the dimensions and relations provided across the sketch.
• Generating of tab by providing the thickness value.
• Adding of flanges on edges of tab as per the design requirement.
• Closing the corners of the flanges between the adjacent faces.
• Creating of hem flanges on either ends of the flanges, in order to enclose the box assembly.
• Mirroring the body by selecting the mid plane, to generate complete box.
• Creating of dimple operations on the tab surface by creating a sketch profile on either side and at the bottom surface.
• Unbending the tab surfaces to perform further operations.
• Creating beads on the tab surface by aligning them as per the design requirement.
• Rebending of the sheet metal by selecting the bend surfaces to regain their actual shape as of the design geometry provided.
• Creating of an extrude surface in order to generate lid on top of box.
• Breaking corners of tab and flange edges by giving certain radius values.
• Generating of hinge points on the right side of the box.
• Generating of normal cut-out on the hinge points as per the design and dimensions.
• Drafting is done based on the various orientational views as required. 

     7.Tools and Features used:

Sketch tools:

Sketch tools are the basic commands which are normally used to create any geometry. Ex: line, circle, arc, rectangle etc.

Tab:

It is a command which is used to generate the blank sheet metal based on the curve or sketch profile selected, by providing thickness.

Flange:

Flange is a command, which is used to get a bend surface with respect to any surface or edge which is correspondent to it.the flange depends on various inputs such as length, relief, width, angle, type of flange, bend radius etc.

Hem flange:

Hem flange is a command, which is used to generate a coil structured or circular type flanges, such that it has various types of hem flanges which helps to lock the two surfaced by creating a hem flange. This command requires bend radius, type of flange, length, edge to execute successfully.

Close corner:

It is a command, which is used to close the corners between two adjacent bend faces. This command requires bend faces and type of corners with radius.

Normal cut-out:

It is a command, which is used to perform a cut-out with respect to each surface planes correspondingly. This command requires a profile direction and depth to execute the operation.

Extrude:

Extrude is a solid based feature command, which is used to create a solid body having a certain thickness. The extrude command requires a closed profile, depth value, direction of travel to execute successfully.

Unbend:

Unbend is a command, which is used to remove the bend of a component temporarily by flattening the surface. This command tends to unbend sheet metal surface by keeping any one of the adjacent surfaces as its stationery surface.

Rebend:

Rebend is a command which is used to rebend the sheet metal surface which are unbended previously. This command requires the bend surfaces which are needed to be bend exactly in previous stage.

Dimple: 

It is a command, which tends to indent on the sheet metal surface which are selected. The dimple also acts as punch, such that the sketch or profile selected for dimple decides the exact shape that needs to be acquired at the end. This command requires depth, curve, and rounding radius to generate a dimple on any surface.

Hole:

It is a command, which is normally used to create a hole. This command requires a point as its sketch profile, diameter and type of hole and depth respectively to execute the operation successfully.

Bead:

Bead is a command, which tends to lift the metal surface from its base.it requires the sketch profile, rounding radius, depth and direction to lift the surfaces respectively. Beads are created across the any sheet metal surface in order to increase the stiffness and strength of sheet metal externally.

Mirror:

It is command which is used to mirror or copy the feature or any body to transform and place on other side of the model. This command requires a perpendicular plane to execute the operation successfully.

Break Corner:

Break corner is a command, which tends to provide fillet for corner or edges selected. This command requires an edge and the radius value in order to execute the operation successfully.

Flat pattern:

Flat pattern is a command, which tends to create the flat surface of the formed sheet metal surface. This command requires the base face as its input value to generate the clear flat pattern for any formed sheet metal surface. This flat pattern view can be viewed by changing the orientation tool.

  8. Modelled Components:

         Feature tree of box assembly

                  Front view

  bottom view

         isometric view

   side view  

      top view 

9. Drafted views:

  

 

 

6. Conclusion:

The design of sheet metal box assembly has been generated successfully, as per the dimensions provided in geometric model. The final product of the box assembly tends to appear as the exact replica of the given model, and also the drafting is been carried out for various orientation. The NX CAD tends to make the design accomplishment easier within time constraint for the design engineer.