602 



Popular Science Monthly 



rivets should be hammered with a punch 

 below the surface of the raybestos. The 

 only additional attention required is oc- 

 casional lubrication of the bearings, and 

 tightening of the screws which regulate the 

 spring tension, to compensate for the grad- 

 ual wear in the raybestos linings. 



The all-steel plate clutch requires packing 

 with some lubricant at intervals. For this, 

 the plates should all be removed, wiped off 

 and greased with a thin coating of heavy 

 grease into which a generous quantity of 

 flake graphite has been worked. Flake 

 graphite will be found to adhere longer to 

 the disks than the granulated form. 



The all-steel clutches may be made much 

 more flexible and smooth by substituting 

 molded raybestos disks (obtainable from 

 almost any motorcycle dealer) for some of 

 the steel disks. These raybestos disks are 

 not secured in any way and merely serve as 

 floaters or separators to keep the steel 

 plates from sticking together. The usual 

 steel disk clutch contains from eight to 

 eleven steel disks. If four steel disks are 

 eliminated and two raybestos disks added, 

 the clutch will be made very smooth, jerk- 

 ing will be eliminated and the clutch will 

 seldom require lubrication. 



A tight short drive chain is a frequent 

 cause of clutch trouble, throwing an undue 

 strain on the bearings. Unnecessary tight- 

 ness of the chains also breaks the rollers, 

 stretches the chain and wastes power. , 



Several troubles are encountered with 

 steel disk clutches used on some of the 

 1913-1914 motorcycles. In these clutches, 

 the spring tension is regulated by screwing 

 in a plate which forces the springs against 

 the clutch disks. The central threaded 

 hole in this plate is about 3 in. in diameter 

 and the thread is the fine motorcycle 24 

 standard, and screws on a shaft extension or 

 hub. After the clutch has been taken 

 apart a few times, the thread becomes 

 worn and it is impossible to screw on the 

 plate against the spring tension. The 

 usual method of screwing this plate on by 

 means of a hammer and punch or blunt 

 chisel is not conducive to thread conserva- 

 tion. With the usual number of disks (8) this 

 clutch has an excessive amount of surface. 

 If a couple of disks are left out, the clutch 

 will work as well, and it will enable the 

 plate to be screwed in on good threads 

 which will hold against the spring tension. 



Another trouble is in securing the control 

 clamp to the thrust-bearing collar. Rough- 

 ing the thrust-bearing collar on an emery 



wheel or inserting a piece of emery cloth 

 underneath the clamp will be found to 

 prevent this from slipping. 



Continual slipping of the clutch which 

 does not respond to tightening of the 

 springs is generally due to the springs being 

 weak. The remedy is new springs. 



In adjusting the clutch controls, be 

 careful not to have the thrust-bearing so 

 tight as to prevent the clutch from going all 

 the way in. When the clutch is in tight, 

 there should be some play in the bearing. 



Always leave the clutch in when the 

 machine is not being used. If the clutch is 

 left out, the springs will soon lose their 

 tension. — Wesley G. Paulson. 



New Clay Pigeons That Break with 

 a Single Shot 



THERE is probably nothing more ex- 

 asperating to the expert trap shooter 

 than to know that he has struck a flying 

 target and yet to see it soar gracefully away 

 as if no shot had touched it. A clay pigeon 



has been brought 

 out that will do 

 away with such 

 an annoyance, 

 for it will break 

 if hit by but a 

 single shot. 

 In making these pigeons the inner part 

 is chilled suddenly from a heated condition. 

 This tends to make them very brittle. 

 The material used is a species of glass, al- 

 though the finished product is still known 

 as a clay pigeon. — H. C. Ridgely. 



CHILLED INNER SURFACE 

 The strain causes the 

 clay to break easily 



An Alarm Clock for Awakening 

 the Deaf 



HAVING been awakened by a light 

 suddenly turned on in his room, a 

 deaf man devised an alarm clock to arouse 

 him each morning by this method. An 

 ordinary alarm clock was purchased at a 

 department store and electrical attach- 

 ments were made to turn on the current for 

 the light. A high candlepower light was 

 hung from a pull-switch socket placed near 

 the sleeper. The clock is wound and set 

 in the same manner as any alarm clock. 

 Attached to the winding key is a spool on 

 which is placed a cord. The loose end of 

 the cord is tied to the pull-chain of the 

 electric socket. When the time arrives for 

 sounding the alarm the revolving key and 

 spool take up the cord and thus turn on 

 the light.^ — Frederick J. Knob. 



