Page:Popular Science Monthly Volume 90.djvu/310

 294

��Popular Science Monthly

��length and sharpen the spur. Drive two smaller nails for drive-spurs and sharpen them in like manner. The distance from the center of the driving-spurs may be varied to suit the work in hand. A screw- center may be made by passing a wood screw outward from the center of another wooden face-plate wheel. A simple strip of wood may be used in place of the wheels.

Drilling may be done in the lathe by using square shank, bit-stock twist drills. Screw a wood wheel to the face-plate, find its center and cut a square tapering hole to receive the shank of the drill. Remove the tool-rest and in its place set a small but strongly made box about lo in. high and 5 in. wide. On the lower side of the box, nail a strip of wood i in. square. This strip slides in the channel in the lathe-bed and keeps the box from turning around. Move the tail-stock up to position and use the tail-screw for advancing the work against the drill. The material to be drilled rests against the left side of the box, and the screw bears against the right side. If round material is to be drilled, gouge out a semicircular channel in a wooden block, place it against the side of the box, and let the material lie in the channel.

The jig-saw is supported by a baseboard 26 in. long, 6 in. wide and i in. thick, which is bolted to the bed by using the bolt from the tool-rest. The baseboard is slotted to receive the bolt. The standard which supports the saw-arms is fastened to the baseboard by a tenon and wedge, as shown. The standard may be of 2 by 3-in. stock. Added strength may be given to the standard by attaching a common shelf- bracket. Cross strips are nailed to the saw-table and to these strips and the base- board are nailed four supporting strips. The ends of the saw-arms are slotted to receive two pieces of flat iron each 2}4 in. long, ^ in. wide and 18 in. thick. These are drilled to receive the pins which pass through the arms, and the wing-bolts used for clamping the saw. The construction of the tightener for the saw is plainly indicated in the drawing.

The saw is driven by means of a 34 by 3-in. bolt inserted about ij^ in. from the center of a hardwood face-plate wheel, attached in place of the spur center. The head of the bolt should be countersunk into the wood and should be placed next to the face-plate, so that the bolt cannot by any chance come out while the saw is in use.

��A Hand-Brake for a Flexible Runner Sled

AVERY efficient brake for the modern flexible steel sleds may be constructed of the following materials:

2 small hinges and screws

4 bolts J^-in. in diameter and 2^ in. long

2 bolts }i-in. in diameter and i J-^ in. long

I coil spring

I piece of tire-iron 3 in. wide and 6 in. long

I piece hardwood 24 in. long by I in. square

I piece of hardwood 12 in. long, 3 in. wide

and I in. thick I piece hardwood 2 in. longer than width of

sled and 3 in. wide by l in. thick

The long piece of wood should be rounded off on one end for a handle, then the three

��The parts of the brake and how they are attach- ed to the sled

���pieces of wood are bolted together and the hinges screwed on as shown. After this part is complete the tire-iron is bent into an L-shape and two 34-in. holes drilled in one surface and bolted to the end of the i2-in. piece. The brake is then ready to be put on the sled, by screwing the hinges to the long narrow pieces of the sled which run parallel with the runners. The spring is fastened between the 12-in. piece and the under side of the sled in such a way that it prevents the brake from dragging. A pull on the handle will force the iron into the snow and stop the sled. The spring holds the handle of the brake level with the top of the sled and is out of the way until needed to stop the sled. — Wm. a. Leech, Jr.

�� �