Page:Popular Mechanics 1928 01.pdf/164

 

Crankcases have not been lapped by hand in the plant of the Marmon Motor Car company at Indianapolis since J. W. Anderson, mechanical engineer of the company, built, at a very low cost, a machine that does the work better, and saves 47 cents on the cost of each crankcase. A discarded radial drill press, reclaimed from the junk heap, is the principal part of the apparatus. The crankcase is fastened to a rotating vertical arm of the press and is given a supplemental to-and-fro movement by an eccentrically driven shaft. Ground glass was formerly used as the lapping compound. Worn-out sand from sand-blasting machines has replaced the ground glass. Mixed with coal oil, this sand has been found more satisfactory than the ground glass.



 

In the absence of a regular piston-ring compressor, an excellent substitute can be made from a piece of 2-in. clock spring, about an inch longer than the circumference of the ring, and a piece of stout cord. Insert the piston in the cylinder as far as the expanded ring will permit, fit the clock spring around the first ring to be inserted, anchor the cord to a stud or other fitting, which will enable it to lie flat on top of the cylinder block, wrap it once around the clock spring and pull it tight. As a result the ring will be evenly and positively compressed and the first ring will slide into the cylinder. Loosen the cord, remove the spring and repeat the operation for the other rings.



 

A method of connecting two cocks so that one handle can be used to control both is shown in the accompanying drawing. This idea is being successfully used in connection with filling an inclosed tank with the correct amount of liquid required to make a mixture used in the printing business. The inlet cock is attached to the tank upside down, at the top, and the outlet in an upright position at the bottom. The handle is a piece of flat steel bent at right angles at both ends with square holes to fit over the squares on the plugs. Sockets are brazed to the tank to receive the cocks, one of these being brazed in place with the wrench assembled. When this is done, one faucet must be open and the other shut. Thus, if the inlet is open the tank will be filled, and when the outlet is open the inlet is automatically closed. As soon as the tank is emptied the outlet is closed, which automatically opens the inlet again, filling the tank ready for the next measure.―Harry Moore, Montreal, Can.



¶ Graphite should never be used on an engine timer as it may cause short-circuiting of the current.