Advanced Sheet Metal Design Using NX Cad Challenge_6_Bracket
DESIGNING A SHEET METAL BRACKET IN NX
OBJECTIVE
To create a simple bracket using the sheet metal tools in NX
INTRODUCTION
Software
Formerly known as Unigraphics, NX is an advanced CAD/CAM/CAE owned by Siemens PLM Software. It utilizes a parasolid geometric modeling kernel and is mostly used when advanced modeling features are required in a product. The ownership of the software belongs to the American Software company, Siemens (owned since 2007).
The NX 10 version has been used in this project.
Sheet metal
One of the fundamental forms used in metalworking, sheet metals are thin pieces which can be cut and bent into a variety of shapes. Thickness can vary from 0.5mm to 6mm. This process has been employed in this project to ensure a realistic approach in designing the part.
Target Model
The target model used in this project is a simple sheet metal bracket. Usually used for mounting components, brackets can take a variety of sizes depending on the load to be carried. The model used in this project is an L-shaped bracket.
DESIGN PROCESS
Flowchart of processes
Features and tools used
- Sketch: Line, Point, Fillet
- Sheet Metal (Bend): Contour Flange
- Corner: Break Corner
- Punch: Bead
- Feature: Normal Cutout, Hole
- Form: Unbend, Rebend
- Flat Pattern
- Drawing: Base View
DESIGN PROCESS
UNITS
All dimensions associated with this project are in Millimeters.
DESCRIPTION OF PROCESSES
- The sketch for the base of the model was created in the front plane (XZ plane). The base was then created using the Contour Flange feature, which extrudes the sketch along a specified vector (in this case, the Y direction).
Fig1: Base Sketch
Fig2: Contour Flange feature
- The required shape for the bracket was then created by trimming away a portion of the material. This was done using the Normal Cutout feature which projects a sketch onto the model to remove material.
Fig3: Normal Cutout feature
- The sharp corners of the base feature were smoothed using the Break Corner feature to give the corners a rounded appearance.
Fig4: Break Corner feature
- A sketch for creating a punch feature was created on the XY plane.
Fig5: Sketch for the Bead feature
- To create the punch feature, the model needed to be flattened. This was achieved with the help of the Unbend feature which used the bent corners as inputs to flatten the model.
Fig6: Unbend feature
- The punch feature to be created for this model was a bead (elongated recesses to increase the sheet stiffness) and this was created using the Bead feature which referenced the previously created sketch to achieve the result.
Fig7: Bead feature
- The model was then reverted to its original state by using the Rebend feature on the straightened corners.
Fig8: Rebend feature
- A sketch point was created on the top face to act as a reference to create holes in the part. The points chosen as input for the Hole feature included the previously mentioned point (sketch) and two arc centers atg the bottom edge of the part (when viewed from the top).
Fig9: Hole feature
- A flattened view was created for the purpose of drafting by using the Flat Pattern feature.
Fig10: Flat Pattern View
STANDARD VIEWS
Front View (Fig11)
Top View (Fig12)
Side View (Fig13)
Isometric View (Fig14)
Feature Tree (Fig15)
DRAWINGS
- The drafts of the model were created using the Drafting feature under the Application ribbon in the command manager. Two drafts were created with one referencing the flat pattern view and the other depicting the detailed view of the model.
Flat Pattern Drawing (Fig16)
Detailed Drawing (Fig17)
CONCLUSION
The bracket model was successfully completed with the aid of the powerful sheet modelling tools in NX.