Advanced Sheet Metal Design Using NX Cad Challenge_1_Casing Design
Title
Modelling of a casing using Siemens NX Sheet metal
Objective
- To create a sheet metal casing using Siemens NX Sheet metal
- To obtain a detailed drawing sheet image of the casing
Introduction
Siemens NX software is a flexible and powerful integrated solution that helps us deliver better products faster and more efficiently. It is used for: Design (parametric and direct solid/surface modelling), Engineering analysis (static; dynamic; electro-magnetic; thermal, using the finite element method; and fluid, using the finite volume method) and Manufacturing finished design by using included machining modules. Here we use the feature from NX to create a casing.
Design methodology
The detailed design includes design conceptualization, prospective product drawings, sketches and geometric modelling.
Here also we use similar procedure for modelling.
Description
The tools used while the procedure is explained below. When we create a new sketch, a dialog box pop-ups asking us to define the Sketch Plane. The screen will display the sketch options. We can choose the Sketch Plane, direction of sketching and type of plane for sketching. When we create a sketch using the Create Sketch dialog box, we can choose the plane on which the sketch can be created by clicking on the coordinate frame as shown. This will highlight the plane we have selected.
We use sketch curve tool bar sketch. This toolbar contains icons for creating the common types of curves and spline curves, editing, extending, trimming, filleting etc. Each type of curve has different methods of selection and methods of creation.
Line option will selectively create only straight lines.
Studio Spline can create basic spline curves with poles or through points with the desired degree of the curve.
Dimensional Constraints: The degrees of freedom can be eliminated by giving dimensions with fixed entities like axes, planes, the coordinate system or any existing solid geometries created in the model. These dimensions can be linear, radial, angular etc. We can edit the dimensional values at any time during sketching by double-clicking on the dimension.
Geometric Constraints: Besides the dimensional constraints, some geometric constraints can be given to eliminate the degrees of freedom. They include parallel, perpendicular, collinear, concentric, horizontal, vertical, equal length, etc
After the creation of sketch, we use some features to model the casing. Lots of them are available in groups.
First e will select a plane and create a rectangle in that plane. After finishing the sketch, we will use tab icon tocreate the solid.
We can remove some materials by ceating a new sketch on desired plane and using normal cut out tab. We can easily modify the solid by using bend option. For that, first we must create reference lines. The bend tab will help us to change the shape of the model accorrdingly.
We can simply create flanges by using flange option and selecting the edge to be flanged.
Fillets for the sharp corners can be given by break corner option.
Dimple is added by using dimple command and a reference curve is required for this. It is created by studio spline and it is rotated by curve rotation. Bead is also created by repected command and it is mirrored by mirror command.
Final images of the casing is given below. They are isometric, front, left and top views respectively.
Now we create a basic view in drafting. The Drafting Application is designed to allow industry standard engineering drawings directly from the 3D model or assembly part. Drawings created in the Drafting application are fully associative to the model and any changes made to the model are automatically reflected in the drawing. The Drafting application also offers a set of 2D drawing tools for 2D centric design and layout requirements.
Conclusion
Modelling and drafting of the casing was completed.