Page:Popular Science Monthly Volume 88.djvu/313

 Popular Science Monthly A Way of Fastening Machine Parts

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��IN building models of machines, en- gines, etc., the amateur is sometimes confronted with a case somewhat like that shown.

The shaft A is of small diam- eter; the hub of the gear B is a great deal larger than neces- sary, requiring a large diam- eter taperpin C. If this pin is driven in as shown in Fig. i, it will weaken the shaft, but if the pin is driven in as shown in Fig. 2, the shaft is only weakened slightly. The pin C in Fig. i can shear or break or twist at points D, but when the pin is driven as shown in Fig. 2, this is impos- sible and the shaft and pin will carry a far greater load than the old conventional way of pinning as shown in Fig. i.

��it was discovered that the carriage could not be moved far enough to the right to allow the cross slide on which the tool is mounted to be moved in and out, it lacking only a few inches.

���Old method of pinning on the left; new and efficient way on the right

��A Capacity Job OME small stands had

��SOME small stands had been de- signed both to length and size at the bottom so that they would fill the lathe completely. When it came to facing the top and bottom of the stands

���The tailstock was fastened down by means of two bolts passing through a wide plate. The bolts were taken out and the plate removed. The plate used for holding the center rest down was used instead. As this plate was only one-half as wide as the regular plate, it was fastened under the left- hand bolt of the tailstock, thus allow- ing the tailstock to be moved back far enough. The carriage could now be moved to the right, thereby allowing the cross slide to shift in and out.

Before being able to run the car- riage close up against the tailstock it was necessary to remove the split nut used in thread cutting, as this nut struck the lead-screw and feed-rod bearings. The drawings show clearly how the gain was made.

��A

��By means of the arrangement shown in

the lower cut, the lathe is able to take

larger stands. The upper cut is the

original arrangement of the lathe

��A Good Belt Compound.

CiOOD Ix'lt cominmnd is made from equal parts of resin and light machine oil. Boil the mixture for about 20 minutes. Use when cool by pouring a little, drop by drop, on the moving l)elt. Not only will a good gripping surface be secured, but the compound will also act as a preservative.

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