Hobbing: (Previous)
Gear hobbing is a multipoint machining process in which gear teeth are progressively generated by a series of cuts with a helical cutting tool . Both the hob and workpiece revolve constandly as the hop is fed across the face width of the gear blank. With gear hobbing the cutting action is continuous , and as many as four or five teeth my be cut at the same time.
(Manufacturing processes reference guide ; Robert H. Todd,Dell K. Allen,Leo Alting , pg.59 ; Özgür Cebeci 030060158)
Hobbing: (New) (Better) (Manufacturing Technique, Tooling)
Forming single or (most important ) multiple mold cavities by forcing a hob into relatively soft steel blank. Hobbing is a technique where a master model in hardened steel is used to sink the shape of cavity into a heated mild steel or an alloy such as beryllium copper. The hob is larger than the finished plastic molded product. After hobbing, the metal cavity shrinks as it cools to the required shape.
(Plastics Engineering, Manufacturing & Data Handbook, Dominick V. Rosato,Donald V., p.374)
Staking: (Previous) (Better)
Staking is a process that is specially suited to connect parts made from dissimilar materials. One part is provided with studs, which protrude through holes in other part. The studs are then deformed through the cold flow or melting of the plastic to form a head which mechanically locks the two components together. It is a quick and economical technique and it has an advantage that no consumables such as rivets and screws are required.
Staking is widely used in many fields like, automotive industry, telecommunications, electronics, medical equipment and consumer appliances
(Manufacturing Technology-I, Gowri, page 407)
Staking: (New) (Squeezing Process)
Staking is a method of permanently joining parts together when a segment of one part protrudes through a hole in the other. Ashape punch is driven into the exposed end of the protruding piece. The deformation couses radial expansion, mechanically locking the two pieces together. Because the tooling is simple and the operation can be completed with a single stroke of a press, staking is a convenient and economical method of fastening when permanence is desired and appearance of the punch mark is not objectionable.
(Degarmo's Materials and Processes in Manufacturing, E. Paul DeGarmo,J. T. Black,Ronald A. Kohser, p.433)
Overhead Cost: (Previous)
Overhead cost in present cost accounting practice is the
portion of total cost that cannot be directly traced to particular operations,
products, or projects. Indirect expenses should be allocated, utilized, and
added to the unit cost estimate. The problem with allocating overhead
charges is that these costs often exist even if the product is not produced.
Companies, based on their activities, may adopt different techniques in
measuring the overhead cost. Overhead charges may be determined in
different ways including:
1. Overhead as a ratio of direct labor dollars
2. Overhead as a ratio of direct labor hours
3. Overhead as a ratio of prime cost
The product cost is the summation of the material cost, direct labor plus
overhead cost, and the total tooling cost. The cost of the product can be
obtained by charging the overheads to the operation product cost.
(Emad Abouel Nasr,Ali K. Kamrani, Computer-Based Design and Manufacturing An Information-Based Approach, pg.57)
Overhead Costs: (New) (Better) (Accounting)
All product costs other than direct materials and direct labour are put into a category called manufacturing overhead also is known as factory burden or indirect manufacturing costs. Costs are included as manufacturing overhead if they cannot be traced to the cost object of interest. The manufacturing overhead cost category contains a wide variety of item, Examples of manufacturing overhead costs include depreciation on plant buildings and equipment, janitorial and maintenance labour, plant supervision, material handling, power for plant, utilities, and plant property taxes. The important thing is to remember is that all cost in the factory is classified as direct materials, direct labour, or manufacturing overhead. No product cost can be omittedfrom classification, no matter how far remote you might think it is from the actual productionof a product.
(Cornerstones of Managerial Accounting, Maryanne M. Mowen, p.37)
Automated Inspection: (Previous) (Better)
Traditionally, individual parts and assemblies of parts have been manufactured in batches, sent to inspection in quality-control rooms (post-process inspection), and, if approved, put in inventory. If products do not pass the quality inspection, they are either scrapped or kept on the basis of having a certain acceptable deviation from the standart. Obviously, such a system lacks flexibility, requires the maintenance of an inventory, and inevitably results in the approval and passing of some defective parts.
In contrast, one of the trends in modern manufacturing is automated inspection. This method uses a variety of sensor systems that monitor the relevant parameters during the manufacturing process (on-line inspection). Then, using these measurements, the process automatically corrects itself to produce acceptable parts. Thus, further inspection on the part at another location in the plant is unnecessary. Parts may also be inspected immediately after they are produced (in-process inspection).
(Kalpakjian, Smith; Manufacturing Engineering and Technology 4th Edition ; pg 998)
Automated Inspection: (New) (Assembly Process, Quality-Control)
Automated inspection stations can be integrated within the assembly operation to check any critical part or step to ensure that defects do not reach the next station. This is particularly important for a critical part housed within the assembly. By detecting the problem in real time, during the assembly processes, the cost of repairs is minimized.
Automated inspection equipment is expensive, but with carreful attention to its versatile features, including its process controller, it can be reprogrammed and adapted for future operations. just as with robot selection, consult with the machinary supplier to develop a clear understanding of a machine's features for current and future uses. The quality of your customers product may depend on and demend this type of inspection equipment.
(Total Quality Process Control for Injection Molding, M. Joseph Gordon, Jr.,M. Joseph Gordon, p.501)
Return on quality (ROQ): (Previous)
Quality standards are essentially a balance between several considerations; this balance is also called return on quality (ROQ) and usually includes some limit on the expected life of the product.
(Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, Ed. 5th, p. 1112)
Return on quality (ROQ): (New)(Better)(Quality Optimization)
ROQ is the quality-specific term for the same manner of cost benefit analysis that has long applied to almost every other business operation from production to marketing. When the return on investment in any given quality initiative fails to meet the company's minimum return on investment requirements, ROQ policy requires the termination of that initiative. Advanced practitioners of ROQ would also required that proposed quality projects pass a cost-benefit analysis before being adopted.
The implications of ROQ policy is clear. Quality managers who cannot prove conclusively that their departments produce meaningful net gains in their companies' performance will be subjected to traumatic reductions in their department budgets, Their personal influence within the company, and -in many cases- their very job security.
(Optimizing quality in electronics assembly: a heretical approach, James Allen Smith,Frank B. Whitehall, p.8)
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