318 FARM MACHINERY REPAIR 



f acturer before beginning to repair or adjust any part of a 

 belt-driven machine. The points suggested here under 

 working instruction can then be carried out with a much 

 greater degree of intelligence. 

 288. Repairing a Grain Separator. (Fig. 325.) 

 Working Instruction: 



1) Cylinder Renew all badly-worn, bent or otherwise dam- 

 aged teeth. Tighten all loose teeth, and see that the 

 cylinder is firmly keyed to the shaft. If cylinder bearings 

 are worn, they can be made to fit snugly by removing 

 shims. If the bearings are badly worn, they should be 

 re-babbitted or new bushings put in. (See instructions 

 on babbitting at end of this exercise.) Examine the shafts 

 for rough spots. If necessary, smooth them up with a 

 fine file and emery cloth. After the cylinder shaft and 

 bearing are in first-class condition, the cylinder should be 

 carefully balanced before the bearings are adjusted. This 

 is necessary when a number of new teeth have been 

 added. To balance the cylinder, provide two saw horses 

 or other suitable stands to support the ends of the cylin- 

 der shaft. Level up the supports and place on them 



* 



pieces of smooth steel, on which the cylinder is to rest. 

 Place the cylinder on supports and allow it to revolve. 

 Mark the top of cylinder where it came to rest and roll it 

 over again. If it comes to rest in the same position as 

 before, it will indicate that the opposite side is heavy. Pro- 

 vision is made on some cylinders to counterbalance this 

 by driving slugs of lead into the holes in the ends of cylin- 

 der. Where no provision is made, new teeth can be put 

 in on the opposite side, or wedges can be driven in under 



