Advanced Sheet Metal Design Using NX Cad Challenge_2_Box Assembly

TITLE OF THE PROJECT: Advanced sheet metal design using Siemens NX cad - Box Assembly.

OBJECTIVE: To design a box assembly and create a draft of it using Siemens NX 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 metal working, 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".

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

a roll sitter.

NX Sheet Metal: Creating fast, accurate flat patterns is the goal of any organization that manufactures products which

contain sheet metal parts. NX Sheet Metal provides a set of tools within the NX design environment that allows for simple

and fast design of sheet metal parts, dependent on their material and manufacturing process, the most common of which

is straight brake sheet metal forming. With NX Sheet Metal, formed and unformed representations of the parts are created

closely following the industry workflows and best practices for bending calculations, tooling, and sheet metal features. The

value lies in improving quality and reducing cost of sheet metal parts by producing an accurate sheet metal pattern as the

correct input for part manufacture, whether internally or to a supplier.

DESIGN METHODOLOGY

Design methodology is explained by the flow chart as follows;

• Create A new file.
• Rectangular base is created using tab command.
• Box walls created using flnge command of lenght 200mm.
• Coners areclosed using the closed corner feature.
• Flange and hem flange are used to lock the walls ofthe box.
• Aprofile is created onone of the side walls of the box.
• A dimple is created using the previous profile.
• Using mirror eature the dimpleis mirrored on the opposite wall.
• Another rectangular shape dimple is created on the base of the tab.
• Two beads created on the base of the tab using bead and mirror feature.
• Hem flange is created on the top of the foure walls.
• Adatum coordinate ( Datum CSYS) Is created at the free end of the tab.
• Part is mirrored to create a complete box using the morror body commond.
• Both the bodies are united to create a single body.
• Lid is created using tab feature on a datum plane ( 203 mm upward).
• Flanges are created on he four sides of the lid.
• Lid is then mirrored using the datum CSYS and mirror body command.
• The Top parts are combined to create a complete lid using the command unite.
• Using tab,breake corner,flange,hem flange and normal cut out features hinge is created on the wall.
• Another hinge is mirrored Adjancent to it by using mirror body command.
• Similarly , ahinge is created on the lid.
• Flat pattern is created separetly for the lid, box,top and bottom hinges.
• Drafts are created for all the patterns.
• END

DESCRIPTION

Sketch:- It is the basic of any design.

Tab:- It is used to create base feature of a sheet metal by extruding a sketch along a vector by a thickness value. Here tabs were created as the base of the top and bottom hinges as well as the base of the box.

Flange:- It is used to create an extended part (bend) of a sheet metal. There are total twelve flanges created in the box assembly.

Unbend:- This feature is used to unbend the adjacent bends and flatten them. Here it is used to create cut outs for the hinges.

Rebend:- It is used to rebend the corners that were bent before along with any features added after the unbend feature.

Dimple:- It lifts an area of the model inside a sketch that simulates a stamping tool. Here three dimples are created,i.e., in the middle of the base and two at the sides of the box.

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. There are total four beads created around the dimple at the base.

Normal cutout:- It cuts the material by projecting a sketch onto the model and then cutting perpendicular to the faces intersected by the projection. Here a rectangular shaped cutout was created to create the top and bottom hinges.

Mirror feature:- It copies a feature and mirrors it across a plane. Here the dimple on the side wall and beads on the bottom of the tab are created using thisfeature.

Hem flange:- It modifies the model by folding the edge of a sheet metal flange over onto itself for the purpose of safe handling or to increase edge stiffness. It is used to create flanges on the walls of the box, on the sides of the lid and also on the hinges.

Break corner:- It rounds or chamfers a sharp corner of a tab or flange. It is used in the tab created for hinge.

Closed corner:- It closes a corner where two adjacent flanges meet by extending the bends and flanges. It is used to close the gap between the flanges used to create the walls of the box.

Mirror body:- It copies a body and mirrors it across a plane. Box, lid and hinges are mirrored as a body using this command.

Unite:- It combines the volume of two or more bodies into a single body. Two box and lid parts are combined using this feature to create a single body.

Flat pattern:- It creates a flat pattern feature from the formed sheet metal part. Separate flat patterns are created for the box, lid and the hinges.

Datum plane:- It creates a datum plane used to construct other features. It is created to form the lid.

Datum coordinate system:- It creates a datum coordinate system used to construct other features. It is created as a reference to mirror the bodies and the features.

IMAGES

Following are the images of box assembly in different views;

Front View -

Side View -

Left View -

Right view -

Top view -

Bottom View -

Isometric View -

Drawing Sheet -

CONCLUSION -

By performing this task, I have learned how to use features like tab, flange, break corner, closed corner, dimple, hem flange, bead, rebend, datum plane, datum coordinate system (Datum CSYS), flat pattern, mirror feature, mirror body, unite, normal cutout and unbend by creating a box assembly.