DRIVEN by three sets of rubber bands, this little motorboat hull-a scale model of the 13-foot boat, the Vagabond-attains an astonishing speed. It planes on top of the water exactly like a large speedboat and skims along for more than 100 feet.
When powered by a spring-operated toy model of an outboard motor such as that shown in the accompanying illustration it will run about 200 feet at a speed of from 4 to 5 miles an hour.
The hull is a %-inch scale model of the 13-foot Vagabond, a combination rowboat-motorboat that many people have built with great success. The over-all length is 19 11/16 inches, the extreme beam 6% inches and the weight 8V2 ounces. If a rubber band motor is used, either two or three sets are required, and these should consist of seven strands each.
The framework should be constructed of spruce, and for the planking material use clear 1/32-inch white pine, cedar or mahogany. The bottom may be pine or cedar, and the sides and deck mahogany.
Draw full size paper patterns of the frames, transom and stem; then mark and saw out the frame parts. Lay the frame material on the patterns so as to conform to the outline, and glue together with waterproof casein glue or a quick drying nitrate base cement.
The completed frames are next notched for the keel, chines and inwale. The stem is glued and attached to the keel with two V4-inch brads. Mark on the keel the correct spacing for the frames.
It is necessary to make a form on which to assemble the framework. This form is shown at the bottom of the accompanying drawings. When it has been set up in a convenient place to work, fasten the keel temporarily to it. The various frames are then glued and fastened from the inside to the keel with one 1/2-inch brad to each frame. Be sure to level and line the frames up before the glue sets.
Starting at the transom, glue and nail the chines to the frames. Drill lead holes for the brads. Fasten the chines on both sides simultaneously. Spring clothespins make excellent clamps to hold the parts in place until the glue dries. Tie the chines together at the stem until the glue is thoroughly set.
The inwales are next glued to the frames, but make sure first that the frames are properly lined up. The after and forward ends of the inwales are glued and nailed with 1/2-inch brads.
The forward motor hook is bent to shape from a 1/16-inch brass rod. Drill the stem and insert the hook as near the top of the stem as possible. Embed the outside of the hook firmly into the stem.
Glue the deck beams in place, and temporarily set small wood strips between frames Nos. 4 to 8 so as to prevent undue strain on the frame joints when the planking is applied. The corner brace or knee and the inside coaming are now glued in position.
The planking on the original full size boat was divided into three strakes on each side, and eight strakes on the bottom. To simplify matters, the model is constructed with one 1/32 by 1/4-inch batten on each side, and two battens of the same size on the bottom. These are carefully notched into the frames and glued.
Complete working drawings for a 1/8-inch scale model of the 13-foot Vagabond. The frames should be laid out full size on paper so that the parts can be cut and assembled accurately. The gear can be bought, if desired.
View showing framing. Note the batten for the side planking.
The side planks are each attached in one piece, but the bottom planks in four pieces. While the 1/32-inch planking is thin enough to bend easily, it is best to soak the pieces in hot water and bend to the required shape as accurately as possible by hand. When dry, glue the planking to the framework.
Plank the sides first; then remove the hull from the form and carefully trim the projecting edges flush.
On the bottom begin by gluing the two planks nearest the keel. These are cut to shape so that the seams will meet in the center of the bottom battens. Soak the bottom planks in hot water and shape them by hand before gluing.
Fill any defective spots in the seams with a plastic wood composition. Sand the hull smooth and apply two or three coats of varnish or lacquer inside.
Glue in 1/32-inch decking to the deck in two pieces, with the seam in the center. Deck seams may be simulated by cutting faint lines in the deck about 3/8 inch apart.
With the decking in place, glue the 1/32-inch coaming, end piece, and sheer plate in position. Allow 1/8 inch of the coaming and end piece to project above the sheer plate.
Moldings 1/32 by 1/8 inch are glued to the sheer to give a finished appearance to the hull and make it look shipshape.
A false outer bow stem 1/16 by 1/8 inch is soaked in water and bent to shape so as to fit the outer edge of the bow. This piece covers the bow and the edges of the planking at this point.
Paint the hull below the water line bright green, and make the 1/8-inch boot-topping white, striping it on as neatly as- possible. The remainder of the hull is then varnished. Rub with fine sandpaper between coats.
The gear drive is built as indicated on the plans, or the gear assembly may be purchased from a model airplane supply house. The gear assembly is fastened to the keel with 5/16 by inch machine bolt.
The underside of the hull showing propeller and rudder.