Written by Tim Bailiff
Build It
As seen in the Fall 2021 issue of Park Pilot
Why not build two? Tim Bailiff first built this yellow prototype.
Full-size plans Click here for full plans - Sheet 1
Tiled plans Click here for tiled plans - Sheet 1
SPECIFICATIONS:
Model type: Park flyer
Skill level: Beginner builder/intermediate flier
Wingspan: 6 inches
Length: 6 inches
Power: 6mm x 15mm coreless 15,000 Kv motor
Propeller: 1-3/4-inch Gemfan
Battery: 80 mAh 1S 3.7-volt LiPo
Radio equipment: Spektrum DX7 or similar DXM2/DSMX transmitter; E-flite (EFLU6807) all-in-one receiver
Materials List:
>> (1) E-flite U6807 all-in-one receiver/ESC unit
>> (1) 12 x 12-inch 2mm Depron foam sheet
>> (1) 1 x 1 x 1/32-inch plywood
>> (1) 6mm x 15mm coreless 15,000 Kv motor
>> (1) Venom 70 mAh or compatible 80 mAh 1S 3.7-volt LiPo battery
>> (1) 1-3/4-inch (clockwise) Gemfan propeller
>> (1) Roll of 1-inch Blenderm medical tape
>> (1) Roll of 2-inch clear packing tape
>> (1) Roll of 2-inch colored packing tape
>> (1) 6-inch .020 carbon-fiber rod
>> (1) 6 inches of .015 music wire pushrod
>> (1) 2 inches of 1/32 clear heat-shrink tubing
>> With the COVID-19 pandemic creating an abundance of “home time,” how about building a super fun, little airplane that you can fly in your own front yard? What is so special about round airplanes? Well, a round model is a unique design because its wing is a disc. Yep, the wing is perfectly round.
Even more interesting, this particular round airplane’s wing is only 5 inches in diameter and is completely flat! In fact, it’s roughly the size and shape of a DVD, but constructed from 2mm Depron foam.
The Fly’n-A-Round is easy to build, requires few parts, transports well, and is super fun to fly. Now, I’m not stating that it is super easy to fly. On the contrary, some experience is required to fly this little aircraft. In fact, even experienced pilots might note a slight learning curve. But once you get the hang of it, what fun you will have! Are you up for a little challenge? If so, please read on.
First, I recommend reading this entire article before you begin building. It really helps to know which step comes next. With a little preparation, this airplane will practically fly off the building board (pun intended). Along with the construction photos, I’ve also provided full-size 81/2 x 11-inch plans. Simply download them and print them on standard-size printer paper. Cool, right?
In addition to the materials list, a few other things are needed, such as glue, which I will cover as you need them. As for the transmitter, I used a Spektrum DX7 version 2. Any transmitter that uses the DSM2 or DSMX modulation would work fine with the recommended receiver.
Building: Let’s start with this airplane’s most distinctive feature: its round wing. The wing is cut from 2mm Depron. In fact, the entire airframe is cut from the same 2mm foam. I used a drawing compass to help with cutting the round wing.
My X-Acto knife fit perfectly in the pencil holder and made it a simple process. One technique I learned is that after lightly pushing the tip of the knife into the foam, you can carefully rotate the piece of foam sheet around the point of the compass instead of rotating the compass itself. It works great!
Using the plans as a template, trace the fuselage and fin on waxed paper. Lay it on your Depron and cut it out in one single piece. There are only two pieces to the entire airframe! What could be easier?
By the way, a 1-foot square piece of foam can make multiple Fly’n-A-Round airframes! Because you are going to make one, why not make another?
Elevons: Before gluing anything together, decide which will be the aft end of your wing and cut out the two elevons. Drawing a centerline from front to back can help with orientation. Remember to leave 1/4-inch of foam between the elevons. Cut the underside leading edges of both elevons back at a 45° angle. This will permit them to move fully into their down positions.
Use a 1/4-inch-wide length of Blenderm tape to hinge both elevons. Remember to leave a slight gap at the front and center to allow for free movement.
Now would also be the perfect time to install your tape spar on the underside of your wing. Simply turn your little round wing over and lay a piece of clear 2-inch packing tape wingspan-wise, perpendicular to the centerline. It should cover the entire forward 2 inches of your round wing. Use the photos for clarity. That’s it—good job!
The 5-inch round wing was cut from 2mm Depron foam.
A drawing compass with a hobby knife in its holder was used to cut out the wing.
The elevons are visible on the underside of the beveled leading edges.
A top view of the elevons with their 1/4-inch wide Blenderm tape hinges.
Electronics and battery: The tiny E-flite U6807 receiver unit is the heart and soul of your little Fly’n-A-Round. This amazing piece of microelectronics combines a receiver, an ESC, and two servos onto a circuit board that is smaller than a postage stamp. It can be purchased online through a number of websites or repurposed from an E-flite Mini Vapor or Vapor Lite.
When you have the unit on hand, use the plans and photos to determine its proper location on the wing. For now, just set it in position, with the gears facing forward. Your battery is mounted on the forward underside of the wing. You will need to cut a small hole in the wing to pass your battery leads through. Do this just ahead of the front left of your receiver.
Test-fit the fuselage over the receiver unit to ensure that it won’t interfere with servo movement. Cut away any foam from the fuselage as necessary.
The 70 mAh and 80 mAh LiPo batteries that I used were purchased online. Venom (venompower.com) makes a nice 70 mAh LiPo battery, but I chose a different route. I purchased several FB-651417 80 mAh LiPo batteries on Amazon then soldered on my own Molex PicoBlade (molex.com) connectors. They were slightly lighter and offered better performance. I found that Velcro self-adhesive dots work great for mounting the battery on the forward underside of the wing. Use the plans and photos as necessary.
Motor and propeller: The motor that I chose was a 6mm x 15mm coreless motor purchased online from Micro Motor Warehouse (micro-motor-warehouse.com). I found that the 14,000 Kv motor provided plenty of power. I paired it with a Gemfan 45mm propeller that I purchased through Amazon. The propellers come in sets of two. I chose to use a clockwise-rotating propeller.
The method by which you connect your motor to your receiver is up to you. Because the new receiver unit that I purchased already had a Molex-type connector on its ESC lead, I chose to shorten my motor’s lead and solder on a compatible Molex PicoBlade connector. My finished shortened length was 1-inch long and I used small 1/4-inch lengths of 1/32-inch heat-shrink tubing to insulate the solder joints.
Push your little 45mm propeller onto the motor propeller shaft then connect your motor to the ESC and bind your receiver to your transmitter. You will want to set your transmitter to Delta mode and test that it properly functions. Correct as necessary in your transmitter settings and remember to center your servos. If you find that your motor spins in the wrong direction, simply unplug it and reverse the motor leads.
Now you are ready to mount the motor to the fuselage. You should slightly sand the top and bottom of the metal motor housing to give it some “tooth” for gluing. Split the motor leads over the top of the fuselage and slide the motor into place. You will notice that a few degrees of downthrust are built in, but you will also need to angle your motor a degree or two to the right. Glue your motor in place using foam-safe CA. Use the adhesive carefully and sparingly.
Assemble the airframe: This part is easy! First, using a generous drop of hot glue, secure the receiver unit squarely onto the wing where you previously test-fit it. Ensure that the geared ends of the servos are facing forward. Using either foam-safe CA or 5-minute epoxy, glue the fuselage/fin piece into place. As the glue sets, make sure that the fuselage remains straight along the centerline and the fin stays vertical. Simple, right?
Control linkage: Okay, it’s time to connect your elevons to your servos. Start by making the two small 1/32 plywood control horns. Remember to drill the tiny .015-inch holes as indicated. Sand lightly, then use foam-safe CA to glue them into the proper positions on each of the elevons. Note that they slant slightly forward toward the hinge line.
The pushrod assemblies are constructed next. Make two as indicated on the plans. The Z-bent wire ends are held in place using 1/4-inch lengths of clear heat-shrink tubing. After heating and securing the wire ends, connect the pushrods to the servos. Gently twist and remove the wire ends from the elevon ends of the pushrods.
Insert the wires into the plywood control horns then reinsert them into the heat-shrink tubing. A touch of thin CA glue applied where the Z-bent wire enters the heat-shrink is all that remains. Do this only to the elevon ends of the pushrods. Hey, your Fly’n-A-Round is all built!
Make it your own: Now it’s time to decorate your airplane and make it your own. I used colored packing tape on my wing. It’s a small model, so brighter is better.
For my tail art, I used clear Avery full-sheet label paper and printed it using my computer. One trick that I learned is to lightly spray the finished artwork with a clear finish, such as Rust-Oleum. This prevents the ink from running should it get wet. After the clear coat dries, cut out the artwork and apply it.
Grass is your friend: This is what you’ve been waiting for—it’s time for your airplane’s maiden flight! I always suggest finding a grassy area at which to test-fly your new models. This airplane is no exception! Although your Fly’n-A-Round is lightweight and surprisingly robust, concrete and asphalt are terribly unforgiving. If your front yard is grassy—perfect! If not, go find some grass, perhaps at your local RC flying field.
Ready for takeoff: After connecting and securing your battery, perform one final prefight check. If everything looks good, you are ready to go! Facing into the wind while grasping the wing in your hand, advance the throttle to full and give your little airplane a very brisk “Frisbee-like” push out and up, at roughly a 45° angle. As you do so, use you elbow more than your wrist. Be forewarned—there might be a bit of a learning curve to successfully launch your airplane, but you can do this!
Remember, a little “flick” is not what you want because launching too slowly will be followed by an immediate roll to the left. Be ready to correct for it. If your attempt to recover fails, simply cut the power before impact. On grass, it will just bounce and you can simply pick it up and try again.
When you’ve mastered the launch, the fun really begins! You’ll find that the Fly’n-A-Round is a spirited little flyer. With 80 mAh batteries, flight times last just a few minutes at full throttle. A small reduction in power really helps.
When you are comfortable with how it handles, consider trying some aerobatics. It can be a bit of a handful, but that’s what makes it fun!
When it’s time to land, fly it all the way down. It’s no glider, so use plenty of power to land (plop) it onto the grass.
I really hope that you enjoy building and flying your Fly’n-A-Round. Encourage your friends to build one too. How fun would a gaggle of these little airplanes be? They are simple and inexpensive to build, easy to transport, and loads of fun to fly.
The fuselage/fin pattern has been drawn on waxed paper, placed on the foam, and is ready to cut.
This view of the fuselage shows the motor placement with its shortened motor leads.
The E-flite receiver/ESC all-in-one unit.
The underside of the 80 mAh LiPo battery is shown here. Remember to cut a pass-through hole in the wing for the battery leads.
The motor and receiver/ESC installation are complete.
The completed pushrod connections to the elevon control horns can been seen.
Tim created this tail art on a computer and printed it.
I wish you many enjoyable flights, my friend, and as always, stay safe and stay well. Fun stuff …
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