77G 



Popular Science Monthly 



Plane Blade Clamp and Emery 

 Wheel Guide 



WHEN sharpening a plane blade or 

 a chisel i in. or wider, it is difficult 

 to obtain a true edge even when both 

 hands arc free; and since the advent of 

 the small hand-power wheels it is still 

 more difficult where only 

 one hand is available for 

 guiding the tool. The 

 guide shown here is in- 

 tended to counteract the 

 difficulty. 



The clamp which holds 

 the plane blade, Fig. i, 

 is made of iron, with the 

 exception of a small oak sliding block. 

 A strip of iron 8 in. long by i3^ in. 

 wide and }/s in- thick can be procured at 

 a hardware store or blacksmith shop. 

 Heat it' red hot and bend it over an 

 anvil or vise to bring it to the necessary 

 form, as shown in 

 Fig. I. When it is 

 sufficiently cool 

 touch up the 

 rough surface 

 with a file or 

 emery wheel. 

 Procure some J<^- 

 in. round iron 

 rods, cut them 

 the required 

 lengths, according 

 to the design, and 

 thread with a ma- 

 chine-screw die, 

 14: in. by 20 or 



24 threads. Make the holes for the ad- 

 justing screws with a 3/ l6-in. twist drill 

 and tap them with }i-in. by 20 or 24 tap. 

 The handles on the screws are made of 

 short pieces of nails set snugly in a ^ s-i"- 

 hole. 



The sliding 

 block of oak on 

 the horizontal ad- 

 justing screw is 

 about I in. by 

 1 3-^ in., and per- 

 haps 3''2 in. thick, 

 allowing sufficient 

 <le[)th for the long 

 screw to be seated 

 in it. Make a small groove on tin- end 

 of llic screw nearest the block and |)ul in 

 u brad to keep the screw from drawing 



Fig. 1. The clamp which holds 



the plane blade is made of iron 



with an oak sliding block 



away fnjm the block. Before attaching 

 the block, rabbet the lower corner which 

 will overlap the plane or chisel blade, or 

 inlay a small strip of fairly stiff brass in 

 the top of the oak block, setting it with 

 glue, .so as to form a wearing surface for 

 the vertical screw, as when sharpening 

 a narrow blade the oak 

 block may come under 

 the screw. In order to 

 have the emery wheel 

 and guide always in line 

 and set up square it is 

 well to have the wheel 

 clamped to a board which 

 can be used as a pcr- 

 then the device can be 



S/D£ l^/£iV 



£NO Vf£lV 



Fig. 2. The wheel is clamped to a board which 

 may be used as a permanent base for stability 



fND VIEW 

 OfRUHWAy 



sioe vicKf 



Fig. 3. The runway may be made of wood and 

 should be twice the length of the sliding cl.nmp 



manent base; 

 fastened to the workbench as a unit or 

 hung out of the way when not in use. 

 The runway itself is made of wood, as 

 the wear is very 

 slight. It should 

 be at least twice 

 the length of the 

 sliding clamp. 

 Have it about ij^ 

 in. wide by 5i^ in. 

 thick. With a 

 rabbeting plane 

 take ofT the top 

 to the depth of 

 J^ in., lea\ing a 

 small raised edge 

 about J s '"• by 

 3/^ in., which is to 

 guide the clamp, 

 as shown in the 

 detail in Fig. 3. 

 Another way would be to screw on a 

 thin metal strip, raising one edge 'g in. 

 above the top of the runway. Fasten 

 a small angle iron at each end of the 

 them to the sliding 

 support on the 

 right, and to a 

 "jcQpcrmancnt sup- 

 port on the other 

 end. Small bolls 

 with thumb mits 

 will render the 

 runway adjust- 

 able, so that a 

 b 1 a d e c a 11 be 

 ground at any 

 <lcsirr(l angle. The runway should 

 be si t up at a |)erfecl right angle 

 to the center of tiie wheel. 



runway. Secure 



