Advanced Sheet Metal Design Using NX Cad Challenge_5_Odd Shaped Enclosure

Objective:

To design odd shaped enclosure and its flat pattern in NX cad Sheet Metal Application.

Introduction:

Sheet metal is metal formed by an industrial process into thin, flat pieces. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes. Countless everyday objects are fabricated from sheet metal. Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate steel or structural steel.

There are many different metals that can be made into sheet metal, such as aluminium, brass, copper, steel, tin, nickel, and
titanium. Sheet metal is used in automobile and truck (lorry) bodies, airplane fuselages and wings, medical tables, roofs for buildings
(architecture), and many other applications.

NX Sheet metal application has advanced features that can quickly convert solid models to sheet metal components, and
create sheet metal parts that enclose other components. These advanced features create a sheet metal model from a generic
solid body by ripping edges, cleaning up geometry, and converting to a sheet metal body.

Design Methodology:

Features Used:

Sketch: The sketch is the fundamental base element for any feature in the 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 the 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 a face.

Extrude: First of all a solid model is created in the sheet metal workbench of NX CAD. The sketch profile of our solid model
is created and then extrude command is used. Extrude Command is used to convert the 2D sketch into a 3D model.
Convert to Sheet Metal: After the creation of the solid model use the command convert to sheet metal from solid which is
available in the sheet metal workbench of NX. The faces and the edges are to be selected which is to be wrapped around
by a sheet metal. After wrapping the sheet metal around the solid body the solid body is hidden.

Flange: After the wrapping of sheet metal features are added like flanges and jogs. Flange is a projecting rim on a flat
object. Flanges can be given to the edges of the model by using the flange command available in the sheet metal
workbench. Flanges are given to the required edges.

Jog: This feature allows a flange or a tab to bend following a specific curve on the surface of the flange or tab and extend it
to its original length. It is like lifting one side of the flange or tab from the curve. In this enclosure, a straight line inclined to
the horizontal is created on the face of the inclined flange of the other side and the jog feature is applied.

Unbend: This is a very powerful and very useful tool in Siemens 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. Once the unbend feature is used, further
features can be carried out using the sketches created in the unbent state.

Beads: Beads are the features added in sheet metal components in order to increase the stiffness of the component.Beads require a sketch in order to apply the feature. It can be either an open or closed profile. For this enclosure, the first
two lines are sketched on the flat surface of the top face which is inclined and is symmetrical to the horizontal line passing
through the midpoint of the vertical edge of the part. The beads of 3 mm depth are then applied.

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. For this casing, first, the four points are sketched symmetric to the x-axis in
position and the hole feature is applied.

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. This is done
using the rebend feature and selecting all the bends in order or by box selection. This completes the design process of the
casing adding the features.

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
within the same component. The flat pattern of this enclosure indicating the bend radius, bend angle, and bend direction
are shown below.

Steps:

Creating solid model

Converting solid model to sheetmetal

Adding flange and jog feature

Unbending

Adding bead and hole feature

Rebending

Views

Flat pattern

Conclusion:

Designed odd shaped enclosure and studied to convert solid modeling to sheet metal parameter and flat pattern technique.