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Written by Joe Hass
FF airplane returns as an RC model
Product Review
As seen in the June 2018 issue of
Model Aviation.



Specifications

Wingspan: 20-3/16 inches
Wing area: 110.8 square inches
Flying weight: 5.6 to 6.75 ounces
Three channels: Rudder, elevator, and throttle
Price: $46.98


Pluses

• It is a complete kit.
• Propeller, motor, ESC, and servos are available directly from Retro RC.
• The airplane is totally cute.
• It is a quick build.




The Ebenezer is a gentle flier that can also be quite aerobatic. It can be flown indoors in larger venues such as a basketball court.



Bonus Video


Product Review

The Ebenezer was originally designed and published in the April 1958 edition of the British Aero Modeller magazine. (Yes it is spelled correctly. It is the Queen’s English.) It was an all-sheet wood, low-performance Free Flight (FF) model. Fast-forward 60 years, mix in laser cutting, micro RC equipment, LiPo batteries, and brushless motors, and you have the makings of a simple-to-build, fun project that can best be described as a Cartoon Scale flying machine. It flies well, indoors or out.

Thanks to Mark Freeland of Retro RC for finding this treasure and working through all of the details to create a fine kit. This is a great project if you are new to building and finishing with balsa wood. In addition to the 10-page instruction manual that is filled with pictures and text, there are detailed plans.

Two versions are available. The Limey is the British version with rounded wingtips. The Hun is the German version with scalloped trailing edges and a distinct resemblance to the Fokker D. VII. Jigs and fixtures that will help you with this and other construction projects are in the Retro RC catalog. A package that includes the propeller, motor, ESC, and 3.7-gram servos is also available from Retro RC.




The competed major assemblies are ready for finishing.


Construction starts with the wings—joining the center sections with each wing panel. Laser-cut hardwood and balsa parts make alignment easy. Simply make sure that you prop up each wing panel as directed to get the proper dihedral in all four panels.

Although I used CA glue, the recommended epoxy would make a more durable joint. Thin fiberglass on the joint will further reinforce the wing joints. A quick once-over with fine sandpaper smooths the surfaces and rounds the leading and trailing edges.

The fuselage is the most complicated, yet it is easy thanks to the laser cutting and instructions. The detailed manual is full of tips to make construction even easier. Resist the desire to sand anything until you are instructed to do so. Work begins with attaching the vertical stabilizer, top wing pylon, and balsa windshield. A neat technique for centering the items is included in the instructions.

Pylon reinforcements are added, along with firewall reinforcements that set the proper right thrust and downthrust. The firewall is assembled from three pieces of plywood that will eventually house the prebent landing gear. Epoxy is again the preferred adhesive to hold the firewall in place.

To gain enough room for the servos and receiver, balsa cheeks are added to each side of the basic fuselage. There is a specific left-side and right-side cheek. There is also a beautiful laser-cut, thin plywood hatch that is held in place with magnets. Thin CA is the preferred adhesive here. Aliphatic adhesives such as Titebond can work as well.

After the cheeks are completed and attached to the main fuselage, the upper and lower wing platforms are glued in place. The wings are attached with rubber bands. Dowels are supplied for both locations. Make sure you install the half dowels that hold the wings centered.

The included wheels are built up from a plywood core with balsa sides and plywood disks for the bearing surface. The wheels are cleverly built—actually glued—on a 1/16-inch drill bit to aid in alignment. When the bit is placed in a drill motor, you can sand the wheel to a pleasing shape. After mine were sanded, I pressed a sharpened #2 pencil into the wood to create a “tire” outline.




Wheels are easily constructed from laser-cut plywood and balsa. The “tire” is painted on.


Some black paint finished the tire section. The rest of the wheel was hand painted to match the airframe color. The completed wheels easily snap free from the drill then #2 O-rings hold the wheels centered on the landing gear.

Hinging the control surfaces is accomplished with the included thread in a figure-eight pattern through the laser-cut holes in each surface. This was how we created low-drag hinges in the early days of RC. Detailed instructions and pictures are included in the kit.

There are many options for finishing. You can leave the wood natural, use iron-on film, or paint it. I brushed on two coats of 50% thinned clear dope as a primer. I simply rubbed my hand over the surfaces to remove the roughness created by the first coats.

I then sprayed Testors Model Master olive drab from an aerosol can on all of the surfaces. A matched brush enamel finished the coloring and touched it up. A variety of brushed or sprayed paints will work. Test your finishing method on some scrap wood before putting the final application on your aircraft.

Decorations are included on a printed sheet of paper. Spray the top of the paper with hair spray to seal the toner then cut out the individual pieces and attach them with spray-on contact cement.

The removable wings make installing the servos and related linkages easy. The carbon-fiber pushrods have metal ends with Z bends to attach to the servo arms and control horns. Heat-shrink tubing holds everything together. After adjustments, a drop of thin CA under each piece of heat-shrink tubing locks everything in place.




Pushrods are made up of carbon-fiber rod, Z-bent wire, and heat-shrink tubing. It is easy to assemble and adjust. The model uses thread hinges with a figure-eight pattern.


I used an APC 6 x 4 electric propeller painted dark brown for a wood effect. The pilot figure was assembled, along with the included scarf, to complete the project.




The motor, battery, and servos are all easily accessible.


Normal-size fingers can easily mask the actual center of gravity (CG) location. Carefully check it. The CG is a laser-cut hole on the top wing pylon. Use sharpened #2 pencils, sharpened dowels, or chopsticks to suspend the aircraft on the CG. If needed, add weight to properly position the CG. Better yet, use a larger battery to extend flight times.

Resist any desire to increase the control throws beyond those recommended for the first flights. The rudder is surprisingly powerful. If your radio has mixing, consider mixing rudder to aileron to make it easier to fly, especially if you are accustomed to flying a four-channel aircraft and used to flying with rudder.

Takeoffs are straightforward. Smoothly advance the throttle. After the tail lifts off, add a touch of up-elevator to break ground. Indoors, I fly at half throttle. Horizontal and lazy eights are easy. For loops—more like a figure nine—I go to full throttle, dive a little, and pull up. Stalls are straight and more of a mush. It spins easily and recovers quickly.

This isn’t a 3D machine, but it can be extremely aerobatic. For rolls, go to high rate, full throttle, and pull up slightly as you apply full rudder. Rolls are barrel shaped. It is a lot of fun.

Work the throttle for landings, gradually reducing throttle and adding some up-elevator to flare. You can experiment with different propellers and control deflection to match your flying style. This is a draggy airframe, so don’t expect much of a glide if you chop the throttle completely.

This is a quick, fun build that will allow your creative juices to express themselves. Flying the Ebenezer is great, indoors or out. Keep it in the car for instant fun anywhere.




The completed model is derived from Bert Striegler’s Ebenezer, first published in the April 1958 issue of Aero Modeller magazine.


—Joe Hass
joehass@gmail.com


Manufacturer/Distributor:

Retro RC
(248) 212-9666
www.retrorc.us.com


Sources:

Testors Model Master
(800) 837-8677
www.testors.com






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