¼-scale FOKKER E.V.

Model Airplane News, Mar 2005 by Johnson, David

Famous WW I German parasol fighter

THE FOKKER E.V WAS THE LAST FIGHTER BUILT by Anthony Fokker for the German Fliegertruppe. It had a plywood-covered, fully cantilevered, parasol-wing configuration.

The E.V was introduced just in time for the 1918 second Fighter Competition, in which it was regarded as the best rotary-powered competitor. The E.V. had outstanding maneuverability and was nicknamed the "Flying Razor." Several early E.V.s suffered from a weak wing construction, but newer versions featured strengthened wings and were designated "D.VIII." Introduced too late during WW I, they never had a chance to distinguish themselves in combat.

My ¼-scale model is designed around the popular Zenoah G-38 engine. I tried to keep it uncomplicated while maintaining a relatively accurate scale outline. Let's get started.

* TAIL SURFACES The stabilizer is pretty straightforward; the outline pieces are made of 3/8-inch balsa, and the crosspieces measure ¼× 3/8 inch. For the elevator halves, use laminated outlines that you form around pins stuck around the elevator top-view plans. Place the pins every ¼ inch or so to maintain an accurate shape. I used Elmer's carpenters' glue to build up the six balsa layers. Laminate all the layers together first, and then work them into place as if they were a solid piece of wood. Wrap them around the pins, and use more pins on the outside of the laminations to hold them in place. Leave the piece alone for at least 24 hours. After the lamination has dried, complete the elevators by adding the straight, inner crosspieces. The rudder is built in the same way.

* WING Build the wing upside-down over the plans. Start by making the two, upper, onepiece ¼-inch-square basswood spars. Use a scarf joint as shown on the plans to join the spar sections, and install a basswood doubler between the two outboard R2 ribs at the joint locations shown on the plans. Place the two spars over the plans (doubler side up), and place the scarf joints as shown on the plans. Glue all the ribs into place on the front spar, and then glue the basswood spars into the wing center panel. Now glue the lower front spars into the outboard sections. Roll the wing back so that the ribs fit onto the rear upper spar, and tack-glue the upper

SPECIFICATIONS

MODEL: Forker E.V.

TYPE: WW I parasol-wing fighter

SCALE: 25%

WINGSPAN: 84 in.

LENGTH: 51 3/8 in.

WING AREA: 1,162 sq. in.

WING LOADING: 25.8 oz./sq. ft.

RADIO REQ'D: 4-channel (redder, throttle elevator, aileron)

ENGINE USED: Zenoah G-38

PROP. USED: Zinger 20×8

spar into place with thin CA. Now glue in the lower, rear, outboard spars. Remove the wing from your workbench, check the structure for warping, and then reglue all the joints with carpenters' glue.

Add the leading and trailing edges and then add the balsa sheet to form the center-section cutout and the trailing edges at the aileron areas. Sheet the bottom of the wing with 3/32-inch balsa, doing the center section first and then the outboard panels. Don't induce any warps into the wing structure. Flip the wing over, and epoxy the lite-ply strips at the strut-attachment locations. Install the aileron servos. I installed my servos permanently, but you can cut hatches in the wing bottom if you want. Route all the servo wires to one of the front strut attachment points.

* FUSELAGE Build the side frames (one on top of the other), and put wax paper between them to keep them separate. Cut the crosspieces to length, and position the two side frames upside-down and vertical over the plans. Install the front three crosspieces (top and bottom), and make certain that the structure is square. You'll remove the lower front crosspiece later. Pull the tail posts together while making sure that the stabilizer area is properly aligned with the plans. Once the glue has dried, flip the fuse-lage over and install formers 1 through 4. Then install Cl through C4, as shown on the plans.

To install the wing struts, place grooved blocks (grooved side down) into their correct positions, cut them to match the contours of the top formers and then epoxy them into place. Cut 1/8-inch plywood to fit beneath the blocks and the fuselage sides, and epoxy them and the ½-InCh triangle balsa stock into place for reinforcement. Run a 3/16-inch drill bit through all the strut locations to clean excess epoxy out of the grooves.

Bend the cabane-strut wires to shape, tape them together, and slip no. 8 wire terminal connectors onto their ends. Place the wing on top of the cabanes and check its incidence; make sure that the connectors fall roughly into the correct attachment area under the wing. I brazed the cabane wires together, but you can bind them with thin wire and silver-solder them together if you wish.

Epoxy the landing-gear blocks into place; then, from the cockpit forward, sheet the fuselage top and then the rear turtle deck and side cheeks, as shown on the plans. Sheet the bottom of the fuselage from the rear landing-gear block to the rear of the cockpit. Leave the area between the firewall and the rear landing-gear block open to allow access to the fuel tank and your radio gear. After you've covered the model, this area will be covered by an aluminum panel.