DFTG 1333 Mechanical Drafting

Chapter 9- Understanding Manufacturing Manufacturing uses the concepts of industrial activity in order to make products. Back in the day they were made by hand. Manufacturing produces Discrete Parts-Individual Parts or Continuous Parts. Products needs to meets the requirements for the product specifications. They must be made by economical and environmental means. Quality must be built into each step of the process from Design to Assembly.

Concurrent Engineering-To optimize all elements of the product during its life cycle. It is hard to implement since it must have the support of upper management and be able to be implemented across the various disciplines. CAD-Computer Aid Drafting aids in making the appropriate models to allow the company to not make costly prototypes. CAM-Computer Aided Manufacturing. It will assist in the programming of the machines involved in manufacturing.

Rapid Prototyping This is costly because of the time and the resources that it takes to generate a physical model. The size of the model and the accuracy takes hours or days to construct. Many of the models have to first be exported to a.STL file format in order to be made. There are limitations on producing the models due to the jagged appearance. This can be limited by have more than 3 axes of movement.

Design Manufacture Assembly Operation

Material Selection Ferrous metals: Carbon, Alloy, Stainless steel Nonferrous Metals: Aluminum, Magnesium, Copper, Nickel, Titanium, Super Alloys, Low Melting Alloys Plastics: Thermoplastics, Thermosets, and Elastomers Composite Materials: Reinforced Plastics, Metal Matrix, and Ceramic Matrix Composites Chemical Properties: Oxidation, Corrosion, toxicity, flammability have to be considered

Manufacturing Processes Table 9.2

Processing Methods Casting-expendable molds and permanent molds Forming and Shaping-Rolling, Forging, Extrusion, Drawing, Sheet Forming, Power Metallurgy Machining-Turning, Boring, Drilling, Milling, Grinding, Chemical/Electrical/Electrochemical Machining Joining-Welding, Brazing, Soldering, Diffusion Bonding, Adhesive Bonding, and Mechanical Joining Finishing-Honing, Lapping, Polishing, Burnishing, Surface Treating, Coating, and Plating

Material Selection Choosing the right type of material allows the proper usage. Such as using hard and brittle material does not allow the shape of the product to be made. You must first look at the application and then choose the proper material that you need. At times due to cost there are limitations as to what you can design due to design restraints, cost, and material selection.

Practical Design Concepts Sharp corners are not the best to make since they are hard to make. Often the rounder edges are better to use. Drilling needs a boss. Figure 9.15

Dimensional Accuracy and Surface Finish Size, Thickness, and shape complexity have majors parts in the Manufacturing Process.

Measuring Devices Caliper-Digital and mechanical Tongs, Tinks

Manufacturing Failure Does not function Becomes unreliable Becomes unsafe