Popular Science Muntldy 



933 



Changing a Boy's Handcar into a 

 Mechanically Propelled Sled 



THE ordinary handcar sold at almost 

 any toy store, or the car operated by 

 foot pedals, is not of much use when i ft. 

 of snow covers the ground, and it is usually 



If the front wheels are removed from the handcar it 

 can be securely fitted over an ordinary steerable sled 

 with room enough to accommodate the driving wheels 



Stored away until milder weather returns. 

 The sled takes its place in outdoor sports, 

 but coasting down hill and sliding across the 

 ponds does not, after all, take the place of 

 a motive power that can be kept up in- 

 definitely on the level, whether on the ice 

 or snow. 



The ordinary hand or foot-pedal car can 

 be mounted on runners and different wheels 

 substituted, and an ordinary steerable sled 

 can be fitted to it with little trouble. First 

 remove all four wheels from the handcar, 

 then fit the sled over it and fasten it down 

 firmly with a few bolts. The handcar 

 stripped of its wheels is so much smaller 

 than the average steerable sled that little 

 trouble will be found in fitting them 

 together. It may be necessary to use a 

 few blocks of wood here and there to bring 

 the parts into a snug, firm fit. 



The main thing is that sufficient room 

 should be made on either side to accommo- 

 date the rear driving-wheels. These are 

 fitted to the axles of the handcar, and may 

 be made from solid pieces of wood i in. 

 thick. The rim of the wheels when placed 

 on the axles should clear the ice by about 

 3^ in. when the sled is standing on its 

 runners. By measuring this distance the 

 wheels can be made the right diameter. 

 Find the exact distance from the hub to 

 the ice, and then with a string form a 

 circle* on a board from which the wheel is 

 to be cut. 



Cut out the circle with a compass saw, 

 then make ten i-in. notches around the 

 rim at regular intervals. Hard wood only 

 should be used for the wheels or they will 

 not stand the strain. Into the notches, 



made in the rim small galvanized pieces of 

 iron are inserted with their sharp points 

 projecting outward and forward. These 

 points are the buckets which give tractive 

 power to the sled when on the ice. If this 

 method is too elaborate ordinary i-in. 

 screws may be used, inserted 

 half their length into the 

 wheel, and then filed so a 

 point will be formed. Even 

 ordinary- heavy nails can be 

 used, driving them in firmly, 

 and filing off the heads to a 

 point. 



The sled is intended to rest 

 on the runners, but the brads 

 of the driving-wheel touch 

 the ice or snow and gi\e trac- 

 tive power. When the hand 

 or foot-pedals are worked, 

 the tractive or dri\ing-wheels revolve, and 

 the brads digging into the snow or ice will 

 give propelling power. If the back wheels 

 are nicely adjusted, three times the speed 

 may be obtained from the motor sled than 

 from the handcar. The reason for this is 

 that there is less friction to ov-ercome. Ice 

 or hard snow may be crossed with ease, and 

 it will even climb small hills. 



Everything depends upon the adjustment 

 of the dri\ing-wheels. If the brads project 

 more than }/§ in. below the runners they 

 will impede the progress. 



o 



Removing a Bushing from 

 a Blind Hole 



FTEN it is necessary to put a blind 

 bushing in a fixture for gaging pur- 

 poses, the bushing being pressed in as shown 

 at A ; then before the job is complete it 

 may be required to remove the bushing, 

 through some error. The usual method of 



XHISEL MARKS 



m 



Two effective methods of removing 

 close-fitting bushings in fixtures and jigs 



remoA'ing the bushing is shown at B. A 

 very effective way is shown at C. wherein 

 oil is run in the hole and a close-fitting plug 

 or plunger driven in with a hammer. The 

 compress oil forces the bushing out and 

 there is no danger of damage being done 

 to the parts. — A. H. W'adell. 



