Advanced Sheet Metal Design Using NX Cad Challenge_7_ Metal bracket-II

OBJECTIVE:-

The objective of the project is to design a sheet metal Bracket using sheet metal application in Siemens NX along with a detailed drawing sheet.

INTRODUCTION:-

Sheet metal is a 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.

A Sheet Metal Bracket is nothing but a projection from a wall or overhangs from the wall to carry a weight. Brackets are often in the form of volutes, or scrolls, and can be carved, cast, or molded. These are manufactured by conducting stamping or die casting operation. These brackets found their application for mounting of any products starting from antennas to TV, projectors or street lights and many more.

NX, formerly known as "unigraphics", is an advanced high-end CAD/CAM/CAE, which has been owned since 2007 by Siemens PLM Software. In 2000, Unigraphics purchased SDRC I-DEAS and began an effort to integrate aspects of both software packages into a single product which became Unigraphics NX or NX

DESIGN METHODOLOGY:-

DESCRIPTION:-

TOOLS USED:-

1.SKETCH :-

A Sketch is a named set of 2D curves and points located on a specified plane or path.You can apply rules, in the form of geometric and dimensional constraints, to establish the criteria your design needs.Features created from a sketch are associated with it, if the sketch changes so do the features

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

3.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 

4.Advanced flange :- Use this command to add a flange along an edge using a bend angle or a reference face. The edge and reference face can be curved.

This command is useful when you want to create non-linear flanges, or when you work with sheet metal support structures in complex assemblies. You can use existing geometry as reference to define the flange dimensions.

When you unform an Advanced Flange feature, the unformed feature is integrated with the feature created by the Sheet Metal Flat Pattern command.

This command works in the same way as the Aerospace Flange command in the Aerospace Sheet Metal application

5.Flange:- Flange command use to add a flat flange at an angle to a planar face and adds a blend between the two

1.Click flange command icon.

2. In the graphics window, select the edge to add a flat flange.

3. In the flange properties group.

• Select full option in the width option list.
• Set the length value in the length box. Click to change the direction if you want. In the length reference box, you can select more option as: inside, outside web, tangent. 
• Select the angle of flat flange.
• In the inset box, you can select the method to inset material as: material inside, material outside, bend outside, material inside OML.
• Select the offset you want.
• Click OK to finish this command.

Note: If you want to use a different bend radius value, you need to draw arcs in the section, or change the default bend radius value.

6.Gusset:- Use the Gusset command to create a stiffening feature on a part.

You can:

• Create strengthening features where extra strength is required in the bend region.
• Create punched or embossed shapes in bend regions of sheet metal parts.
• Specify default dimensions for the Gusset feature using customer defaults.
• Gusset features are represented as centerline curves in the Flat Pattern view

7.Unbend:-

  This feature is used to unbent the sheet metal taking any one face as a stationary face.

Flattens sheet model through selected bends.

To activate command:

• Click on command on (When sheet metal application activated.) “ Home => Form down arrow => Unbend”
• Activate command from “Menu => Insert => Form=> Unbend”

For Using “Unbend” command:

• Activate the “Unbend” command.
• Select the stationary face of the sheet metal.
• Select edges to bend 

8.Rebend:- Rebends, the unbent feature of the sheet metal model.

It uses after the “Unbend” command If needed.

To activate command:

• Click command on (When sheet metal application activated.) “ Home => Form Gallery => Rebend”
• Activate command from “Menu => Insert => Form=> Rebend
• Select unbent faces on the model. (“Select Face” in the “Bend” tab highlighted automatically when command activated.)
• If you want to define stationary face on sheet metal model, click down arrow in the command window to open more options. Click on “Select Face or Edge“ in the “Stationery Face or Edge” tab in the command window. The function will be highlighted. Select stationary face on the model.
• Click the “Ok” to finish

9.Bead:- Used for giving strength to the sheet metals

Bead command to lift material along the contour of a sketch that simulates a stamping tool. Beads can also be created to stiffen sheet metal parts.

• Choose Weld Assistant tab→Sealer group→Bead.

The Bead dialog box opens.

• In the Type group, Ellipse is selected.
• In the Primary Parts group, Select Face is active.
• Select a face on the primary part.
• In the Secondary Parts group, click Select Face and in the graphics window, select a face on the secondary part.
• In the Path group, click Select Curve or Point and in the graphics window select the curve you want to sweep the cross section along.
• In the Parameters group, set the parameters for defining the cross section.
• Click OK to create the Beadfeature

10.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. 

11.Normal Cutout:-   Normal Cutout command to cut material by projecting a sketch onto the model and then cutting perpendicular to the faces intersected by the projection.

You can use planar sketches or 3D curves to specify the section for the normal cutout. If the sheet metal part has multiple bodies, you can specify the target body on which you want to create the normal cutout

12.Hole :- Hole command isto add the following types of hole features in a part or assembly

• General holes (simple, counterbored, countersunk, or tapered form)
• Drill Size holes
• Screw Clearance holes (simple, counterbored, or countersunk form)
• Threaded holes
• Holes on non-planar faces
• Holes through multiple solids as a single feature
• Multiple holes as a single feature

13.Contour Flange:- Use the Contour Flange command to construct a flange by extruding a sketch along a vector, or add material by sweeping a sketch along an edge or chain of edges. The bends are added automatically using the default bend radius value. You do not have to draw the arcs at each bend location. If you want to use a different bend radius value, you need to draw arcs in the section, or change the default bend radius value

DESCRIPTION:-

• First the required sketch for creating a sheet metal bracket was drawn on YZ plane.

• The sketch for creating the Contour Flange was drawn in XZ plane for the required width.

• Then the unwanted portions were removed by using the Normal Cutout.
• The sharp corners were made blunt for the required radius by using break corner.

• Then the unwanted portions inside the bracket were removed using Normal Cutout.
• Then the bracket was unbent for adding additional features like holes, dimple etc.
• For the top v-shaped portion the advanced flange option were used and then created for the required length.

• Now the required holes were created by drawing the required sketch.

• Now the sheet metal bracket was rebend.
• All the sharp corners were filleted using break corner for the required dimension.
• Now the metal bracket was unbend again for adding some more holes and re-bend.
• For the center portion an elliptical cut out was made using normal cutout option.
• Then by using the Advanced Flange option the required flange was created by selecting the edge of the elliptical cut out.

• Finally the gussets were added to increase the stiffness of the metal bracket on either sides of the elliptical cutout on the bend surface.

• Now the metal bracket was completed by creating a drawing sheet with flat pattern view.

DRAFTING SHEET:-

STANDARD VIEWS OF THE MODEL:-

FRONT VIEW

SIDE VIEW

TOP VIEW

ISOMETRIC VIEW

CONCLUSION:

         The sheet metal Recommended workflow to create Metal Bracket II Component  is successfully completed in NX Cad.