Advanced Sheet Metal Design Using NX Cad Challenge_2_Box Assembly

BOX ASSEMBLY

OBJECTIVE:

To understand the step by step procedure to design the casing using NX CAD

INTRODUCTION:

Sheet metal fabrication includes important design considerations to help improve part manufacturability, enhance cosmetic appearance and reduce overall production time.

Sheet metal fabrication is the process of forming parts from metal sheet by punching, cutting, stamping and bending.

3D CAD files are converted into machine code, which controls a machine to precisely cut and form the sheets into the final part.

Sheet metal parts are known for their durability, which makes them great for end use application. Parts used for low volume prototypes and high volume production runs are most cost effective due to large initial setup and material costs.

Because parts are formed from a single sheet of metal, designs must maintain a uniform thickness. We have to be sure to follow the design requirements and tolerances to ensure parts fall closer to design intent and cutting sheets of metal.

DESIGN METHODOLOGY:

TOOLS AND FEATURES USED TO DESIGN CASING:

SKETCH: Sketch is the two dimensional representation of the model, in NX CAD there are different sketch options available to create sketch, the following are the sketch entities available in solid works line, arc, circle, rectangle.

TAB: Creates a base feature by extruding a sketch along a vector by a thickness value or adds a material to a plane face.

FLANGE: Adds a flange to an angle to a planar face and adds a bend between the two.

BREAK CORNER: Rounds/fillet sharp corner.

DIMPLE: Lifts an area of the model inside a sketch that simulates stamping a tool.

BEAD: Lifts a material along a counter of sketch that simulates stamping a tool.

NORMAL CUTOUT: Cuts the model perpendicular to the sketch.

UNBEND: Flattens a bend.

REBEND: Restores a bend.

MIRROR: Mirror tool can copy geometry, surface, curves, patterns and datum features about a mirror plane.

HEM FLANGE: 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.

CLOSED CORNER: Closes a corner where two adjacent flanges meet by extending the bends & flanges.

FLOW CHART:

STEP BY STEP PROCEDURE TO DESIGN CASING

STEP 1: Sketch & create a tab as per the required dimensions.

STEP 2: Create the flange by selecting the edges of the tab as shown in the pictures.

STEP 3: Click closed corner option and select the two edges to close the open corners.

STEP 4: Click on the flange command and select the edges of the previously created flanges and input the required dimensions and repeat the same for opposite edge.

STEP 5: Click on the hem flange option & select the edge of the flange to create the hem.

STEP 6: Click on the mirror option to mirror the selected body & select the unite option to combine two bodies.

STEP 7: Click on the dimple command and the select the sketch which is constructed as per requirement, create the dimple by giving the required parameters & mirror it to the opposite surface.

STEP 8: Construct a circle and select the bead option to create bead. Select the created bead & mirror it on the other three edges of the surface as shown in the picture.

STEP 9: Click on the flange command and select the open edges of the box & input the required dimensions to create flange as shown in the picture.

STEP 10: Create new datum plane at a required height from the working datum plane & create a tab on the new datum plane, this newly created tab is the closing lid for the box.

STEP 11: Create a tab & use break corner option to create round edge as shown in the picture.

STEP 12: Create a flange & hem flange on the edge of the tab.

STEP 13: Select the Unbend option to unbend the edges & use normal cut option to cut the surface as shown in the picture.

STEP 14: Select the rebend option to rebend the edges & mirror the body on to the other surface as shown in the picture.

STEP 15: Create a tab on the top of the lid & use break corner option to create round edges.

STEP 16: Create a flange on the edge of the tab.

STEP 17: Select the Unbend option to unbend the edges & use normal cut option to cut the surface as shown in the picture.

STEP 18: Select the rebend option to rebend the edges.

Final Box Assembly: