Advanced Sheet Metal Design Using NX Cad Challenge_6_Bracket

DESIGN OF BRACKET

OBJECTIVE

The Main Objective of this challenge is to design the Bracket as per given 2-D drawing using the Sheet Metal Operations in NX-CAD.

INTRODUCTION

• Sheet Metal Fabrication is the process of forming parts from a metal sheet by punching, cutting, stamping, and bending.Sheet metal parts are known for their durability, which makes them great for end use applications (e.g. chassis). 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. Be sure to follow the design requirements and tolerances to ensure parts fall closer to design intent and cutting sheets of metal.

• Bending is a process whereby a force is applied to sheet metal which causes it to bend at an angle and form the desired shape. Bends can be short or long depending on what the design requires. Bending is performed by a press brake machine that can be automatically or manually loaded. Press brakes are available in a variety of different sizes and lengths (20-200 tons) depending on the process requirements.

• The press brake contains an upper tool called the punch and lower tool called the die between which the sheet metal is placed. The sheet is placed between the two and held in place by the backstop. The bend angle is determined by the depth that the punch forces the sheet into the die. This depth is precisely controlled to achieve the required bend. Standard tooling is usually used for the punch and die. Tooling material includes, in order of increasing strength, hardwood, low carbon steel, tool steel and carbide steel.

CRITICAL DIMENSIONS

The following are some terminology that are used in sheet metal. Designers need to adhere to machinery guidelines when designing for bending. Bends can be characterised by these parameters. Some critical dimensions that need to be considered when setting up sheet metal in CAD software are sheet metal thickness, the k-factor and bend radius. One needs to check that these factors are consistent with the tooling that will be used in manufacturing. This guide gives important guidelines for good design practice.