432 APPLIED SCIENCE 



The shear, clearance, and cutting edge of shaper tools 

 should be in good condition. Shear is the angle given to the 

 face of a tool, which throws its cutting edge forward into 

 the metal. Tools without clearance drag and pull heavily 

 through the metal. The important features of a shaper are 

 its column, ram, head, stroke, index, table, cross-feed, cross- 

 rail, vise (swiveled and graduated), and driving cone centers. 

 When working on the shaper, the small try-square and the 

 surface block are constantly in use to show when the finished 

 pieces are square with the shaping machine vise, and when 

 one cut is square with another. A graduated universal 

 bevel or a bevel protractor is also employed to lay out angles 

 for planing. A scriber and a 4-in. outside caliper enable the 

 beginner to grasp the first operations of shaping and planing. 

 Cast iron is planed dry, as are steel and wrought iron unless 

 the work is a key-seat, or requires a thin or delicate tool. 

 In this latter case, lard oil is fed to the tool. 



Before starting the planer the ram should be adjusted to 

 the proper length of the stroke. If a piece of work which 

 measures 2J4 in. is to be placed on the machine, the ram 

 should not be set to a 3J^ in. stroke. A sufficient cut for the 

 tool is J4 in., and ]/% in. is even more than enough to allow 

 the head to overreach. These additions then give us a 

 total stroke of 3^ in. and any over this means time lost and 

 unnecessary wear on the machine. 



499. Key-way Machine. The key-way machine is used 

 for the purpose of cutting a slot or a key- way in any thick 

 piece of metal, such as a pulley. The machine is not com- 

 plicated and its operation requires very little skill. A cutter 

 resembling a very coarse file makes the proper width of cut 

 and is held to the work by the machine. 



