Original 1945 Article

The Model Craftsman • August, 1945

HERE at long last is a model plane that has been so simplified that there is no beginner who need be afraid to undertake its construction. Almost a year ago the author decided to design a gas model which would come within the capacities of a beginner. The first requisite would naturally have to be simplicity. Taking this into consideration work began on a highly simplified plane. In so designing, all thought of super performance were cast aside in favor of simple down- to-earth construction.

Upon completion of this job a few test flights were required for adjustments and then the plane was given a "real trial." Seeing its possibilities, the plane was then entered in a Richmond Model Flying Club contest, October 22, at Hicksville, Long Island. It showed real promise this first day by taking Fourth place with a Minute- Twenty average time.

Believing that even this time could he bettered, the author then attempted to combine the same construction with an improved performance. Drag was considerably lowered by streamlining and a Davis Airfoil was included in the wing. This proved to be far better than our expectations warranted. At Creedmore, Long Island, some time later--after an hour of adjustments and low-powered flights--she was opened up wide! On a 20-second motor run the plane vanished after 3 :20, but luckily was later returned.

It has since been entered in two Prop Spinners Club monthly gas contests. In April it took 3rd with a minute, forty-five second average, and in May it received top honors, taking first with a Single flight of Four Minutes and fifty-two seconds. The Average time was 2 :48.

Now, after almost a year of constant designing, building, testing and redesigning this is the final product and by all means it not only combines simplicity of design and top-notch performance, but also that all important "eye-appeal."

But, far from being just a contest model, this rugged little ship often provided a (lay of sport for the mere price of a pair of pen-cells, by combining a short motor run and a "folding" prop.

"Crutch" Strengthens Fuselage

For strength and rigidity, the fuselage is built around a "crutch." This piece of 3/16" x 1/2" hard balsa is the basis of firm construction and must be true to keep the finished ship in good trim. You will note that the crutch, at the front, is spliced to the gumwood motor bearer. This step should be taken first and when the joints are thoroughly dry, proceed to form the crutch. This is done by building it as it would look if you were above the plane looking down. The crutch may be pinned to the table-top while cross-braces are cemented in place. Allow this assembly to dry thoroughly. After this step and without removing the crutch from the plan, the lower (1/8" soft sheet) "outline" keel may be cemented in place. The next step is to cement the lower half of. the formers and 1/8" sq. braces in place. It is advisable to line these up well before allowing the cement to harden.

Next, remove the crutch (with formers) from the (make a "full-sized plan or have enlarged photostat made from drawing herewith) plan and cement the top formers in their proper places. The firewall, which is in two pieces, is clearly shown on the plans. Material used for the bottom of the firewall is 3/16" plywood. The upper half is made from 1/8" hard balsa. Cement the firewall in position after applying the landing gear. The landing gear is attached with tin straps as shown on plans. It would he well to apply a coat of cement to the nuts behind the firewall to prevent their loosening.

With the addition of strigers, you now have a fair start on the "Ascender." Note that these stringers fit into the notches on the firewall and are cemented on top of the other formers. The longerons which have not hitherto been mentioned, are applied at the same time as the stringers. Motor mounts (which go inside the motor bearers) should be varied to fit the motor used. They are held in place by side bolts, as indicated, and the motor is affixed to them also by bolts. The wing platform of 3/16" medium sheet balsa should he well cemented to the top of the main formers, and the overhang should be strongly gusseted. It is advisable to check this to be sure it absolutely in line with the crutch.

In mounting ignition, place all elements as far forward as possible; approximate positions are shown on the plans. Of course, the wiring should be done before covering the plane. The c. g. (center of gravity) should rest at approximately one half the wing chord.

Form the outline of the elevator over the plan (full-sized plan) and insert the ribs. When the cement has (dried, use the "butcher block" (sandpaper block) and sand the leading and trailing edges down to the proper airfoil shape.

Wing Construction

The easiest way to build the wing is to build the entire assembly in one piece. Simply scale up a full-size drawing of the wing and build flat (the dihedral comes later) and allow all joints to dry thoroughly. In this manner it is much easier to have all sections uniform and all joints firm; it also eliminates warping to a great extent. First lay down the spars-then place the ribs in position; next the leading, then the trailing edges. The tips are applied next. The false ribs aid in maintaining the airfoil and eliminate the need 'for sheeting (covering with sheet balsa) the leading edge.

After the wing thus built has dried thoroughly (preferably overnight) it might be well to check all joints before proceeding further. Don't forget to apply those gussets, and don't put in the dihedral formers yet.

When you are satisfied that all construction is solid, get out that old sand block and butcher down the trailing and leading edges to streamline shape. Now, here comes the dihedral forming.

Note that there is a two-inch "V" dihedral to the first break in the wing. Here's the simplest way to make it: -Cut two pieces of wood two inches high; two pieces of 2" x 4,' will work very nicely. Place the wing on the table and at the proper distance, where the first "break" occurs, lay down those blocks. Cut the wing at the center and apply the dihedral formers. Be sure your joints are firm and the cement dried. When the center section is on the table and the two panels rest on the two-inch blocks, pin the assembly in place and let all joints dry a while. Two blocks six inches high are used at the ends of the wings. First cut the joint at the break where you have the two-inch blocks, lay the tip on the 6-inch block, insert the dihedral formers, cement the assembly and rest a while and contemplate your good work while the glue dries.

In covering, avoid using heavy paper; use medium bamboo if available -if not, use double tissue. If you use Silkspan, it is advisable to add one teaspoonful of castor oil to each one pint of dope used. Don't ask us what the castor oil does to the ship's performance, we wouldn't know. Silk may be used for covering the body.

We advise painting the ship red or some other color which has a good visibility factor. Don't make the ship all white -it's too easy to lose in the air.

The "Ascender" will probably require no thrust adjustments; in some cases a degree of down-thrust has been used, but a majority of ships will not need this. As the ship is aerodynamically good in design and incidences are included, very few changes should be made.

First flight should be made with no longer than twelve-second motor runs, using low power. Adjust the ship to fly right under power and right in the "glide." A slight amount of "wash-in" provided in the right wing will prevent any spinning tendency and improve the over-all performance.

So there's the "Ascender"-as fine a model plane as you'll find on any runway.