Popular Science Monthly 

 A Way of Fastening Machine Parts 



285 



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. 



