Page:Popular Science Monthly Volume 89.djvu/631

 Popular Science Monthly

��617

��Benches for Electrical and Mechanical Machinery

THK benches illustrated are designed to meet requirements where strength and rigidity are essential. A bench is shown in Fig. i on wiiich medium weight electrical machinen,- has been tested for a number of years, without the bencii showing any signs of weakening. The top and battens of t his bench are made of 3-in. yellow pine, which can be bought dressed to size, at any mill. The top may be tongued or doweled together as shown in Fig. 3, and can be made the length designated, or ex- tended to 12 or 15 ft. by adding another batten and two more pipe-legs. The battens fastened to the top with ^/^-'in. 5-in. lag-screws; these lag-screws have washers under their heads, is necessary to bore the holes in battens slightly larger than

���FLANCt5 FASTEINED TO FLOOfi AND TABLE WITH *b'.3' LftO SCREWS

��FIG. I.

��ft:^

��A wood-top bench supported by large gas- pipe posts which eliminate vibration

��about J-^-in.

��are

by

to

It

the

the screws,

to allow for the shrinkage

��and swelling of the top. In boring the top for the screws, use a J^-in. bit, running the bit into the wood about ]/2 'I- less than the distance the screw will penetrate; also cover the threads of the screw with soap before turning them in.

While the pipe used for the legs may seem a trifle heavy, it has been proved by experience that to eliminate vibration it is necessary to use this size.- The pipe may be obtained cut to length and threaded on both ends to fit the standard flanges. Screw the flanges on the pipes until

���F1G.2

A bench for light machinery. The strength of the joints is increased by doweling them together

��the bench is the desired height, and par- allel to the floor; then fasten them to the floor and to the battens with ^-in. by 3-in. lag-screws.

Drawers will be found very convenient for holding tools and equipment. They may be made of '^Jt-'"- maple, suspended from the bottom of the bench as shown in Fig. I, which also shows the possible methods of con- struction. Finish the wood parts with four coats of oil-finish, made by mixing i part of boiled linseed oil with 2 parts of turpentine. Apply with a brush and allow it to stand about 3 hours; then nib ofT with a piece of cloth or cotton waste. Each coat should dry 24 hours before applying the next. A finish of this kind preserves the wood and prevents warping.

Another bench for light machinery is shown in Fig. 2. The frame of this bench is made of 2-in. angle-iron, bolted together with ^g-in. by l-in. stove-bolts. The holes for these bolts can be drilled, or if the iron is purchased from a con- struction company, they may be punched at the works for a small extra cost. The top and shelf are made of i>2-in. oak or maple, screwed fast to the frame with i]/i-'in. No. 12 flat head screws. In making the top and shelf, it is ad- visable to use boards not more than 6 in. wide to prevent warping. The mill will supply this stock, dressed and jointed, ready to be glued to- ge t h er. A clamp, such as shown in Fig. 4, to hold the boards together while gluing, is easy to make.

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