Advanced Sheet Metal Design Using NX Cad Challenge_1_Casing Design
Designing of Sheet Metal Casing in NX CAD
Objective:
To design a model of sheet metal casing using the sheet metal design tools application in Siemens NX CAD Software and exporting the model into a 2D diagram.
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 6mm (0.25in) are considered plate steel or “structural steel”
Sheet metal is used in automobile and truck (lorry) bodies, airplane fuselages and wings, medical tables, roofs for buildings (architecture), and many other applications.
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).
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.
As the name suggests, straight brake sheet metal forming uses manufacturing tooling (press brakes) that form the part by bending the metal blanks along linear or straight lines. This is an efficient and cost-effective way to create simple brackets, housings, and enclosures across many industries.
A brake is a metal working machine that allows the bending of sheet metal. A cornice brake only allows for simple bends and creases, while box and pan brake also allows one to form box and pan shapes. It is also known as a bending machine or bending brake or in Britain as a sheet metal folder or just a folder.
(Fig.) Manually driven bending brake
(Fig.) Cornice brake
(Fig.) Hydraulic press
(Fig.) Sheet metal bending in press brake
Brakes come in sizes suitable for light aluminium or brass for small boxes and operated by hand, up to industrial sixed and counterweighted hand-operated or hydraulic machines suitable for large sheets of steel.
With Siemens 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.
In this project we are going to design a model of sheet metal casing in Siemens Nx CAD software.
Design Methodology:
(fig.)Design methodology of sheet metal casing
Tools and Features used while Designing:
Sheet Metal application tools are mainly used in designing the model of casing.
Let’s have a look at the step by step procedure of designing the casing and tools and features used in designing the casing alongside.
First a sketch of rectangle is made in Datum Coordinate plane and dimensioned as required.
All Global parameters of the part properties are changed to 1mm in Sheetmetal preferences.
The following features are find under home tab in sheetmetal application workbench in NX CAD.
Tab:
This feature creates a base feature by extruding a sketch along a vector by a thickness value, or adds material to a planar face. Additional planar selections can be added to generate bends as part of the base feature.
Tab is the base feature applied to every sheet metal part next to a sketch. It extrudes the base sketch of our model.
Normal Cutout:
This feature cuts material by projecting a sketch onto the model and then cutting perpendicular to the faces intersected by the projection.
Normal Cutout feature is used to make a cutout along the left side of the base sheetmetal w.r.t a rectangle sketch in our model.
Bend:
This feature modifies the model by bending material on one side of a sketch line, adding a bend between the two sides.
Bend feature is used to make a bend in the sheetmetal part w.r.t the lines in our model.
Flange:
This feature adds a flat flange at an angle to a planar face and adds a bend between the two.
Flange feature is used to add a planar bend face to the defined edges of our model.
Break Corners:
This feature rounds or chamfers a sharp corner of a tab or flange.
Break Corner feature is used to round the sharp edges that leaning out in our model.
Unbend:
This feature flattens a bend and the material adjacent to the bend.
Unbend feature is used to flatten our model w.r.t the central flat face and the adjacent faces.
Hole:
This feature adds a hole to one or more solid bodies in a part or assembly with options for counterbored, countersunk, and threaded.
Hole feature is used create hole at the extended bodies of our model.
Dimple:
This feature lifts an area of the model inside a sketch that simulates a stamping tool.
Dimple feature is used to create an emboss/lift w.r.t the sketch at the centre of the sketch origin in our model.
Bead:
This feature lifts material along the contour of a sketch that simulates a stamping tool.
Bead feature is used to create a stamp lift of a circle in our model and mirror feature is used to mirror this beads along the model.
Rebend:
This feature restores an unbend feature to its previous bend state, along with any features added after the unbend feature.
Rebend feature is used to bend back our model to previous bent state.
Flat Pattern:
This feature creates a flat pattern feature from the formed sheet metal part.
Flat patterned view can be viewed in our model view tree under part navigator.
Our model in true shading visualization:
Standard Views of Sheet metal Casing model:
Front View:
Side View:
Top View:
Isometric View:
Drawing Sheet:
And finally we exported our model into a drawing using drawing sheet tool in the drafting application in NX CAD.
Conclusion:
A Sheet metal Casing model is successfully designed in Siemens NX Cad Software using Sheet metal application tools and derived as a 2D drawing in a drawing sheet template.