Challenge

Advanced Sheet Metal Design Using NX Cad Challenge_1_Casing Design

GGaya Sudan R18 Feb 2022

TITLE :

Sheet Metal Casing Design using siemens NX.

OBJECTIVE :

To learn Sheet metal design process and to design a sheet metal casing in parametric CAD software Siemens NX following industrial work flow.

INTRODUCTION:

Sheet metal is a metal with a small thickness ranging from 0.5-6mm which is made thin and flat by rolling or hammering process. A number of mechanical components are made up of a sheet metal. Sheet metal is widely used in manufacturing industry due to its various advantages. In this project, sheet metal is designed in siemens NX cad software by following the industrial approach.

DESIGN METHODOLOGY :

The casing designed for this project consists the features like cut-outs, bends, flanges, holes, dimples and beads. Every feature is designed in an order following the industrial procedure to keep the design intent. The design methodology used for this project can be summarized in below flow chart

DESIGN APPROACH :

DESCRIPTION :

SKETCH : The sketch is fundamental base element for any feature in design of any sheet metal component. Most of the features require a sketch. The very first step is to sketch which is then used to create a tab or base feature. So, the first sketch can be called a base sketch. For other features which are the children features of the tab, the sketch may require again on a particular plane or face.

TAB : Tab is the very first feature in any sheet metal component design process. All the other features of the sheet metal in siemens NX are based on the base feature or tab. A tab is created after a sketch is created in any of the planes or datum plane created. The tab is always the parent feature for other features following it. In this casing design the tab is created after a simple sketch in XY plane.

BEND : Bend feature is added whenever a bend in the sheet metal component is required. It may be at any position or at any angle. A sketch is required to create a bend. It can be open profile and it can be either a straight line or a curve.

FLANGE : The flange is an additional face created automatically from any edge of the existing sheet metal component. It is additional material connected to any face or edge which is bent from the respective edge or face. It can be at any position or at any angle.

BREAK CORNER : This feature breaks the sharp edges in the corners and makes it round or adds chamfer. It is like the fillet feature in some other cad software. It prevents the fracture breaking of the sharp corners.

UNBEND : This is a very powerful and very useful tool in NX, it allows all the bends made by the various features to the unbent state at once. In order to achieve a flat configuration of the sheet metal as per the design intent. It is necessary to choose the bends in order, it is also possible to box select all the bends at once.

HOLE : Hole feature in sheet metal design workbench is just like in the model workbench. It can create either simple or counterbore or countersink or tapped holes.

Dimple : Dimple in sheet metal components provide more strength and rigidity to the flat structure of the component. Dimple feature in NX is created using the sketch created in any face or any flange of the sheet metal component.

BEADS : Beads are features added in sheet metal components in order to increase the stiffness of the component. Beads requires a sketch in order to apply the feature. It can be either open or closed profile.

REBEND : All the features added after the unbend feature are added in the unbend state itself. After the addition of sketches and additional features are completed, the sheet metal component has to be rebent to the required position.

FLAT PATTERN : Flat pattern is the representation of the entire sheet metal component in the 2D form of the flat sheet metal with all the bends, cut-outs, holes and additional features in the form of lines or edges. The flat pattern ensures the ability to cut the sheet metal out of the raw sheet metal plate. It removes the possible errors such as interference or collision with in the same component.

DRAFTING : After the design is complete, the execution or the manufacturing of the component requires a technical drawing of the component with the provided scale and with accuracy. The necessary details such as annotations, callouts, bend tables can be added as per the requirement.