Type of Molding Machine
As a matter of fact, such castings were not at all new in this country, having been furnished by American foundries for electrical work for many years. Cast iron springs, piston rings, and many other articles of cast iron are regularly made, which show such elastic quality.
We have said considerable about “castings.” In general we know what castings are, but in the minds of some there may be a little uncertainty as to the manner in which they are produced.
Another of the Many Kinds of Molding Machines
There are few lines of human endeavor which require greater judgment and skill than does the making of molds for castings. Sound judgment based on long experience, knowledge of conditions under which the work immediately in hand must be done, observation, and accurate, deductive reasoning as to the causes of failure are absolutely necessary for success.
Casting, Which Because of Its Length and Small Cross Sections, Requires Very Fluid Cast Iron. (Fig. A)
In general, molding may be said to be done in “pit” or on the “floor” for large work, on the “bench” for smaller work, or by “machine.” Pit, floor, and bench molding are applicable for production of castings of all sizes and descriptions and this general type which we might term “hand molding,” is the form that has been practiced longest. Molding machines are more or less recent inventions which have enabled certain standard shapes and sizes of castings which are in sufficient demand to be produced in great numbers by unskilled workmen and therefore at less cost than is possible by the older hand method.