1926-01-01

FITTING THE MACHINE-TOOL TO THE JOB 260058

The importance of analyzing operations to be performed on a given production job; determining how it can be done best, most quickly and most economically; and adapting standard machines or designing and building special machines for doing the work does not seem to be generally appreciated. Such preliminary work often results in large savings of time in production work, of floor space occupied by the machinery, of scrap losses, and usually in improvement of the quality of the work performed. If it is necessary to develop a new machine for a given purpose the savings effected will often pay for the machine in the first year of its use. The customer should pay all the cost of this development work because very often the special machine is suitable for use by only one customer and on only one production piece and the machine-tool designer and builder cannot recover any losses by building and selling duplicate machines.
The tendency in many cases has been for manufacturers to buy large complicated machines to perform operations that can be done on much simpler units, because the machines have been stock products, but the automobile industry is believed to have reached a stage where the production manager can consider more simplified production. Smaller and simpler machines effect a saving in power required to drive them and also occupy so much less floor-space that they may save the expense of erecting additional factory buildings. An example is given of a machine for boring and bottoming air-cooled-engine cylinders that equals the production of four machines of equal size which it has displaced. One of the main features of this machine is that it permits the loading of cylinders into the machine while the tools are doing their work on other cylinders.
This saving of handling time is exemplified in various other machine-tools that are described and is emphasized because, if the handling of the material can be timed with the machining operations, it may mean that the cutting speed can be slowed down, thereby effecting a saving of tool wear, or the handling can be speeded-up to keep pace with the cutting speed. The important object with all production work is to keep the tools constantly producing chips.
Cylinder-drilling operations that required 13 min. and resulted in a loss of from 25 to 30 per cent of cylinder castings were reduced to 3 min. and a scrap loss of less than 2 per cent by rearranging the locating points for the drilling operation.
Other machine-tools adapted or designed for doing specific jobs include one for finishing the intake and exhaust ports in air-cooled cylinders, one for boring the large and small ends of connecting-rods, one for parting the big ends and making the cut in the small ends at the rate of 500 to 600 rods per day, a small machine for the centrifugal casting of babbitts in connecting-rods, a simple little machine for machining the crankshaft and camshaft bearings in crankcases, another for boring holes simultaneously in opposite ends of crankcases, one for machining transmission cases, a machine that drills holes diagonally in crankshafts and saves a large loss in broken drills, a standard multiple-drill adapted for drilling holes in four directions simultaneously, a drill-press converted into a milling-machine for simultaneously finishing four bosses on different sides of the inside of a small metal case which formerly were finished by back-counter-boring, and a cylinder hone with spring-backed and adjustable abrasive stones.

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