INSTANT JETIFICATION
By Curtis Mattikow
My grandfather used to say, "There are two things they aren't making any more of: land and time." It's funny how, with all these modern conveniences and "timesavers," most of us seem to have much less time on our hands than we used to.
Long evenings spent slicing hundreds of 1/32-inch ribs from contest balsa are not part of the picture for the Average Joe nowadays, including me. It's not that I wouldn't like to — I greatly enjoy the process of traditional modeling — it's that I can't. Given the choice between a placid evening at the workbench making bigger pieces of wood into smaller ones or attending a school board meeting, it's no choice; we all have priorities.
I'm not alone in this. My wife drew a clever analogy between ARFs and TV dinners. After all the things she has to do in a day, to get home and have time to prepare a meal from scratch is a rare privilege.
The early ARFs of the 1970s and '80s were akin to old-school TV dinners — they looked much better in the box-top picture than they did sitting in front of you. You might have had to modify the model and you might have gotten indigestion from the TV dinner, but both were better than nothing.
Thanks to computers, lasers, cheap labor, and evolution, we have come a long way since then. I don't mean ARFs; that's yesterday's news. I'm referring to a new class of model called "receiver ready," also known as RR, or plug-and-play (PIP or PNP). Servos, motor, fan, and ESC are installed in the model; just plug in your favorite receiver and off you go. As in, take your new package from the post office to the field, plug in the receiver, charge it, and go fly.
There is yet another level of prefabrication beyond PNP, which is RTF. Most RTF airplanes include an analog four- to six-channel transmitter and receiver. That adds an errand on your way to the field — pick up eight AA batteries for the transmitter. No biggie!
The cheap radios included with many RTFs are decent with caveats. One I used arrived dead (the distributor replaced it promptly), and the receivers are universally single-conversion. That works fine for park flying, but at a club you are better off with a dual-conversion or spread-spectrum receiver to avoid getting shot down. I tested a few of these cheap radios to the limits of my vision; a simple range check declared any problems early.
Most people who are considering an electric ducted fan (EDF) already own a more advanced transmitter, so almost all these models are offered ready to fly, minus a receiver — hence "receiver ready."
What's in the box
- Prepainted foam airframe with factory-applied decals.
- EDF unit (or units on a twin) with motor and BEC-equipped ESC installed.
- Installed servos with wire extensions tucked away (typically inexpensive mini/micro servos).
- Li-Poly battery (often a low-end 15C pack).
- Charger (often a small quick unit that charges through the balance connector).
- Fixed landing gear with a steerable nose wheel on many models.
ESCs are usually fitted with Deans-style connectors; I received one airplane with an old Tamiya-style connector and changed it in about ten minutes of soldering to match my batteries and chargers.
Most servos are glued in place. It pays to give each a little tug to make sure no one was asleep at the switch during assembly. The inexpensive servos work fine for casual flying, but if you pursue precision flying you'll notice limitations in centering and consistency. You can swap them for micro digital servos, but that runs counter to the instant-gratification nature of these models.
Included chargers surprised me: when tested against my professional chargers, the included versions did the same job. Each cell of a three-cell pack peaked and balanced to 4.2 V (12.6 V total) with no buttons or dials to set. You can use an adapter to plug these chargers into a 110 V outlet at home.
Gear, launching, and landing
Forget bungees; these models have plenty of thrust-to-weight for effortless hand launches. Fixed landing gear is fun for taxiing and pavement takeoffs, and some clubs prefer you not hand-launch or retrieve gearless models from runways. You can remove the gear for slightly better performance and cleaner looks; I noticed an appreciable but not dramatic increase with the gear off.
If you remove the gear, consider clear tape or other skid protection on bellies and wingtips; standard foam doesn't hold up well against rough grass, dirt, or pavement. None of the designs I’ve tested were designed for retracts — installing retracts involves significant engineering and added weight. I have yet to see a retract system for this size that holds up well in daily use; the extra 3–4 ounces matters to performance. My advice: resist the temptation to add retracts.
Upgrades and modifications
RR models generally perform well in stock configuration. Many online threads show owners immediately modifying airplanes to make them bigger/faster/stronger, only to go silent after crashes or component failures. Have faith in the designers: many models are created by dedicated modelers in China working with U.S. distributors to find reasonable compromises in price, looks, and performance.
If you want better performance, start with batteries — try 25C or 30C packs. Better batteries reduce voltage sag and give immediate improvement. I tried MaxAmps 25C packs and felt and heard a clear difference over the stock 18C packs.
For significant power upgrades, consider Don’s RC Wicked EDF outrunner motors (designed specifically for jets). These provide a dramatic boost, but you must also upgrade ESCs and batteries to handle the extra watts.
Avoid fiberglassing foam aircraft. Fiberglass adds far more weight than most expect and leads to a weight-strength spiral: heavier aircraft need more structure, which adds more weight. If you glass enough to make the foam ding-resistant, you may end up with an aircraft as heavy as a carved wood model. In a serious crash, added fiberglass only bundles your shattered foam for easier transport. Foam jets are meant to be light and forgiving; protect them with clear or aluminum tape on bellies and leading edges and handle them carefully.
One useful modification is adding a working rudder. A microservo adds only a few grams but opens new aerobatic possibilities beyond basic aileron/elevator maneuvers. Also, carry extra Li-Poly batteries; with three packs you can practically fly all day.
SPECIFICATIONS
E-Do Model Company (example specification)
- TYPE: Sport-scale RTF
- PILOT SKILL LEVEL: Intermediate
- WINGSPAN: 29.125 inches
- LENGTH: 43.3 inches
- WEIGHT: 24.7 ounces
- POWER: 18L brushless inrunner motor; 25-amp ESC; 11.1-volt, 2200 mAh Li-Poly
- RADIO: Four-channel FM transmitter, five servos, six-channel receiver
- CONSTRUCTION: Prepainted foam, plastic
- PRICE (STREET): $189.95
- FLIGHT DURATION: Five to 10 minutes
- MANUFACTURER/DISTRIBUTOR: E-Do Model Company — 86-755-27571079, 86-755-26195440 — www.e-domodel.com
- NOTES: Current E-Do offerings also include an F-4 and F-35.
StarMax (example specification)
- TYPE: Sport-scale RTF
- PILOT SKILL LEVEL: Intermediate
- WINGSPAN: 28 inches
- LENGTH: 37 inches
- WEIGHT: 19.75 ounces
- POWER: Brushless inrunner motor, 25-amp ESC, 1300 mAh Li-Poly
- RADIO: Four-channel transmitter, six-channel receiver, four servos
- CONSTRUCTION: Prefinished foam, plastic
- PRICE (STREET): $239.90
- FLIGHT DURATION: Five to 10 minutes
- MANUFACTURER/DISTRIBUTOR: StarMax distributed in the U.S. primarily by Hobby Lobby — (866) 933-5972 — www.hobby-lobby.com, www.stx-tech.com
- NOTES: Current StarMax offerings include numerous jet types (F-35, He-162, F-18 in two sizes, F-4, F-5, F-14, F9F, JAS 39, Mirage 2000, MiG-21).
FEATURED MODELS
E-Do F-15
This is one of the most scale-like offerings, with an accurate outline and lots of small details. Construction quality is excellent. The battery box is clever, with a Velcro strap to accommodate various batteries.
Flight characteristics: exceptionally easy to fly and very stable. Rolls are axial and clean; it will loop from a shallow dive with the landing gear on or from level flight without the gear. Takeoffs from pavement are roughly 100 feet; the designer placed the gear to require a slightly longer takeoff roll to discourage premature rotations by beginners.
Power: single motor with bifurcated exhaust keeps it simple and light. The airframe readily accepts power upgrades; with a Don’s RC Wicked EDF outrunner, 30-amp ESC, and four-cell 2200 Li-Poly, the F-15 showed near-unlimited vertical performance.
StarMax F-18
Like the E-Do F-15, this jet uses a single motor with bifurcated exhaust. Exterior detail and paint are nicely done, and water-transfer decals are applied at the factory. It comes in Diamondbacks and Blue Angels schemes.
Performance is terrific and easy to fly. It typically uses an 11.1 V, 1300 mAh Li-Poly and has limited duration (around five minutes) with that pack. You can fit a larger battery with some work, though the F-18 can be a bit nose-heavy to start. It was one of the first in this market and drew a lot of attention.
Freewing L-39
Attractive, easy to see in the air, and extraordinarily stable. The landing gear is strong and forgiving. The exterior finish is well built and painted.
A nice touch: this model has a working rudder linked to the nose gear and will perform a decent knife edge. It ships with an 1800 mAh 15C pack, but performance improves greatly with a 25C pack. With a Don’s RC outrunner and a 4S pack, I experienced unlimited verticals. I’d recommend this as a first jet and it remains interesting for more advanced pilots.
Fly-It-Yourself Su-47 Bekrut
One of the most interesting models in the bunch: a twin, forward-swept-wing design. It’s visually unusual and black, which looks cool. In the air the Su-47 sounds great and draws attention with a wild profile.
Performance is sparkling and extremely maneuverable with a spectacular roll rate. Despite the backward wing, it is stable and lands easily. Construction uses tough, rubbery EPO foam that is CA-safe and highly ding-resistant. Ailerons and elevators are linked, with one servo driving each side.
Kyosho A-6 Intruder
Slightly smaller than the others and the only model here without landing gear — hand launching is easy. Built from very high-density foam, it’s well painted and detailed, competing with the F-15 for scale appearance. Features include a foam scale refueling probe (fragile in transport).
Quality is high, including clear instructions. It typically uses an 1100 mAh, 11.1 V pack (not always included). The system draws roughly 19 A, so a quality 20C pack is required. The Intruder is fast, agile, and looks scale in the air — unique and fun to fly.
Sapac F-22
A bigger, heavier twin compared with many RR models. Well made from dense foam with a good scale appearance and paint job. Flight performance is excellent — quite fast with good vertical performance and better wind handling than lighter models.
Fan units have outrunner motors; the F-22 ships with a 3000 mAh, 11.1 V pack, larger than most other models. The installed outrunners can handle up to five cells, but the stock ESCs usually cannot. I swapped ESCs and tried a four-cell pack; the jet became even more fun. This model retains more energy due to weight, so it requires more room to fly and different maneuver planning, but it’s very satisfying and jetlike.
PRACTICAL TIPS AND CONCLUSION
- Start with the stock configuration before upgrading. Test the airplane as delivered and see how you like it.
- Upgrade batteries first (25C or 30C) for noticeable improvement. If you add more powerful motors, upgrade ESCs and batteries accordingly.
- Protect bellies and leading edges with tape rather than heavy fiberglassing.
- Consider adding a microservo for a working rudder for extra control.
- Carry extra Li-Poly packs — three batteries will let you fly most of the day.
- Keep a minimal tool kit in the car: epoxy, screwdriver, batteries, and a charger for quick field repairs.
It's a great time to be a modeler. When I was a kid I fantasized about full-function jet models that were already built and affordable. Now that fantasy is reality. These foam jets perform well enough to keep an intermediate pilot interested, look fantastic, and let you get your jet fix at local parks while you take a break from more complicated models.
I keep one model in the back of my car, along with five-minute epoxy, a screwdriver, batteries, and a charger. I can sneak in a few flights on the way home from work, and my wife can't smell fuel on my clothes and ask why I'm late.
Curtis Mattikow [email protected]
SOURCES
- Don's RC — www.donsrc.com
- MaxAmps — (888) 654-4450 — www.maxamps.com
Transcribed from original scans by AI. Minor OCR errors may remain.
