Advanced Sheet Metal Design Using NX CAD- Casing Design

                                                      Casing Design in NX CAD Sheet Metal

Objective:

                 The main objective of this project is to design a sheet metal casing in NX cad sheet metal application workbench. Also, to perform the drafting for the casing part.

•       To design and model the sheet metal casing in NX by using some basic features.
•       To learn to create sketches on defined planes as per requirement.
•       To master the user interface and basic features of Sheetmetal application in NX like Tab, Flange, Break corner, Unbend, Creating holes, Rebend, Dimple, Bead, Mirror feature, and Flat pattern.

Introduction:

         Sheet metal Design and Fabrication:- 

                 # Sheet Metal Fabrication is the process of forming parts from a metal sheet by punching, cutting, stamping, and bending.

                 # 3D CAD files are converted into machine code, which controls a machine to precisely cut and forms the sheets into the final part.              

                 # Sheet metal parts are known for their durability, which makes them great for end-use applications (e.g., chassis). Parts used for low volume prototypes and high-volume production runs are most cost-effective due to large initial setup and material costs. 

                 #Because parts are formed from a single sheet of metal, designs must maintain a uniform thickness. Be sure to follow the design requirements and tolerances to ensure parts fall closer to design intent and cutting sheets of metal.

                 #In Sheetmetal application we can create a uniform thickness sheetmetal parts using basic features such as flange, tabs and jogs. We can also do close corners, cutout and stiffening features. The complex sheet metal part can be designed in the solid model workbench and then we can convert it into a sheet metal part. We can also import, clean up and convert a non-sheet metal part into a valid sheet metal part. Flat pattern sheet metal data can be used for the manufacturing process. The Material parameters such as thickness, bend radii and bend relief can be easily set as default settings.

Design Methodology:

                   In this flow chart we are going to discuss step by step Process about model is formed with the Sheet Metal Application.

Description:

             The sheet metal casing has been done with the above flow chart process. While designing the default thickeness, bend radius , relief depth and relief width value are set to 1mm at the Menu → Preferences → Sheet Metal here you can change the Sheet Metal thickness whenever neccessary.

             The sketch is drawn in the XY plane and the tab command is used for creating the base of the part.

TAB:

          Tab – Tab is the basing feature in the sheet metal environment of NX Cad. The tab is the initial or the start-up stage of the design of the sheet metal component. By using the Tab feature, we create a base for sheet metal component and decide the thickness of the sheet metal which is then followed in the further steps of design.

Normal cutout: 

               This command is used to cut the material by projecting the sketch onto the model and then cutting perpendicular to the faces intersected by the projection.

Bend:

              This feature is used to bend the sheet metal as per the reqiured shape.To perform this operation we have to select the face and sketch for bending.

Flange: 

             Flange feature is used to create an extended portion or bend to the selected edge. While creating flange we have to set different parameters such as length of the flange, its angle, length reference (inside, outside, or web), inset (Material inside, Material outside or bent outside). Other parameters like bend radius, bend relief, and Neutral factor are also needed to be considered.

             We used here 5mm length of Flange.

Break Corner:

              This command is used to round or chamfers the sharp corner of a tab or flange.

 Unbend:

            This command is used to unbend the sheet metal. The punching operation can be performed only by unbending the sheet metal.

Hole:

           After unbending all the faces and four holes are made by using the hole feature. In the hole feature we can select the types of hole needed for the requirement.

Dimple:

            This command is Use to lift an area of the model inside a sketch that simulates a stamping tool. We can create an indentation in a sheet metal part using a sketched section as the dimple outline. The Dimple command makes an indentation in the sheet metal part, using a sketched section as its outline.

Dimple Sketch:-

Dimple Feature:-

Bead:

           This feature that we will go over in this post is the Bead. The Bead is like a raised rib in the sheet metal panel. It requires that you have at least one sheet metal panel in the active part as well as an open or closed loop sketch.

           The Bead is another feature that has only a button for Options on the CommandBar.

Mirror Feature:

         This command is used to mirror the bead feature, now we are going to mirror according to 2 planes (YZ and XZ) plane.

Mirror in YZ Plane:

Mirror in XZ Plane:

Rebend:

•     Rebend feature is used to get the original bend shape after performing forming operations like a dimple, bead. 
•     After finishing all these operations, then the sheet metal part should to rebend to check the DFM (Design for Manufacturing) process.

Flat Pattern: 

           This is used to create a automatically flattened version of sheet metal parts and prepare the model for manufacturing process. This flat pattern remains the last feature in the model tree.

                                                                              DRAFTING(Drawing Sheet)

             It is possible to create a 2D drawing from a 3D model using the NX Drafting application. With the 3D model opened at NX, go to File > Drafting. ... This will disables the Modelling application and start the Drafting application.

             It is also possible to add section views to better detail the model. This can be done through the button Section View.

Required settings:

            We want to select the Base view command to show the view of the sheet metal. So, already we have make the Flat Pattern View to useful in the Mnufacturing process Operations. Change the settings in Model view to Flat Pattern then it will show you the flattern Sheet metal.

Drawing Specifications:

Drawing Views:

                                                                          CASING OF SHEET METAL (MODEL VIEWS)

Front View

Side View

Top View

Isometric View

Bottom View

Wireframe View

Conclusion:-

• Sheet metal casing is designed successfully in the NX sheet metal .
• Basic Features of the sheet metal of NX like creating a Sketch, Tab, Flange, Normal cutout, Break Corner, Bend, Unbend, Rebend, Dimple,Bead, and Flat pattern are learned and applied in Design of Casing.