Challenge

Advanced Sheet Metal Design Using NX Cad Challenge_5_Odd Shaped Enclosure

SSelvan It15 Jun 2023

Creating an odd shaped enclosure

OBJECTIVE:

To create an odd shaped enclosure with beads, holes and other features in the sheet metal. To Draft the flat pattern with annotations.

INTRODUCTION:

Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes.

Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate, such as plate steel, a class of structural steel.

Sheet metal is available in flat pieces or coiled strips. The coils are formed by running a continuous sheet of metal through a roll slitter.

In most of the world, sheet metal thickness is consistently specified in millimeters. In the U.S., the thickness of sheet metal is commonly specified by a traditional, non-linear measure known as its gauge. The larger the gauge number, the thinner the metal. Commonly used steel sheet metal ranges from 30 gauge to about 7 gauge. Gauge differs between ferrous (iron-based) metals and nonferrous metals such as aluminum or copper. Copper thickness, for example, is measured in ounces, representing the weight of copper contained in an area of one square foot. Parts manufactured from sheet metal must maintain a uniform thickness for ideal results.

There are many different metals that can be made into sheet metal, such as aluminium, brass, copper, steel, tin, nickel and titanium. For decorative uses, some important sheet metals include silver, gold, and platinum (platinum sheet metal is also utilized as a catalyst).

Sheet metal is used in automobile and truck (lorry) bodies, major appliances, airplane fuselages and wings, tinplate for tin cans, roofing for buildings (architecture), and many other applications. Sheet metal of iron and other materials with high magnetic permeability, also known as laminated steel cores, has applications in transformers and electric machines. Historically, an important use of sheet metal was in plate armor worn by cavalry, and sheet metal continues to have many decorative uses, including in horse tack. Sheet metal workers are also known as "tin bashers" (or "tin knockers"), a name derived from the hammering of panel seams when installing tin roofs.[Reference]

Design Methodology

Draw a trapezoidal sketch. Extrude.
Use sheet metal to solid to Create a sheet metal on the solid part.
Add flanges, jogs or other features on the sheet metal sides.
Unbend.
Add holes, Beads.
Rebend
Use flat pattern.
Draft the part.

NX Commands Used

Sketch - It is the basic of any design.
Extrude - It creates a feature by extruding a section along a vector.
Sheet Metal from solid - It builds a sheet metal model that takes its shapes from a collection of planar faces. This command is used to convert the solid body into a sheet metal body. After selecting the command and the solid body, we can also remove the edge sharpness by removing the material at these places.
Tab - Tab is a command used to create a base for any sheet metal part that can be extruded from a sketch. The sketching plane can be selected as per the designer’s choice.
Flange - It is used to create an extended part (bend) of a sheet metal. It is created at the edge of one side of the model. This command will allow us to select the edge of the base to create a projecting flat extruded surface. The angle, width, length, and type of flange can be determined as per the requirements.
Jog - It modifies the model by lifting material on one side of a sketch line, adding a flange between the two sides. Jog is created at another end of the model opposite to the flange. Jog is a command to lift off one whole side of the part. By selecting a line and the plane, the material can be pushed down or lifted off depending on the situation.
Unbend - This feature is used to unbend the adjacent bends and flatten them. Here it is used to create more features. This command is used to unbend the sheet metal parts to create geometries and work on complicated designs. In this command, we have to select a stationary face and then select the corners of flanges to unbend.
Rebend - It is used to rebend the corners that were bent before along with any features added after the unbend feature.
Bead - It lifts material along the contour of a sketch that simulates a stamping tool, it is used for giving strength to the sheet metal. Here two beads are created on the unbent surface. The selected sketch is lifted off from the base to provide strength to the material. Similar to dimple, the material can be removed in both directions.
Hole - It adds a hole to one or more solid bodies in a part or an asembly with options for counterbored, countersunk and threaded. Here six simple holes are created on the unbent surface with a diameter of 10mm. It can be used to make customized or standardized holes along with a defined point or path. The dept of the hole can be controlled.
Flat pattern - It creates a flat pattern feature from the formed sheet metal part. The user chooses this command to create a flat view of the sheet metal after unbending all the sides and faces. This view can be used in drawing the flat pattern along with the bend radius and other dimensions.[Reference 1]