Electric Formula One Racing - 2010/11
by Michael Ramsey
Overview
Even if you're not a fan of racing airplanes, it's hard not to love any home-built aircraft miniaturized for RC. Since the 1950s, people have been constructing Goodyear-class racers in basements, garages, and city apartments. As RC pilots, we've learned that pylon racers make great sport models: they're light, maneuverable, and fast—if we want them to be.
E-flite's LR-1A Pogo ARF 15e is the first in a series of models suitable for flying in the National Miniature Pylon Racing Association (NMPRA) Electric Formula One (EF1) class. The model is also a great semiscale sport design for pilots who enjoy drawing clean lines in the sky.
Two Pogos were built during the 2010 Pylon Racing Nats in Muncie, Indiana for a provisional EF1 demonstration. One was constructed by a top race team and equipped with the NMPRA-legal E-flite power system; the other was assembled with the recommended E-flite Sport power system to compare handling and performance.
Models at the 2010 Nats
- Racing aircraft:
- Spektrum SH5000 mini digital servos
- DSM2-compatible radio system
- E-flite 60-amp ESC
- Larger motor (high-speed winding) with 4S 2500 mAh battery
- Sport aircraft:
- JR Sport MN48 analog servos
- DSM2-compatible radio system
- E-flite 40-amp ESC
- Recommended 3S 3300 mAh battery
The racing team completed one build on-site between race heats—gotta love their spirit!
Construction and Materials
Construction methods are credited to Jerry Small, whose techniques bring a seemingly complex airframe into a simple-to-assemble ARF package. Contrary to its looks, and despite the complicated history of pylon racing, the Pogo is all wood with plastic and fiberglass parts to round it out—consistent with EF1 rules.
Assembly is straightforward with minimal alignment and fitting tasks. Although the wing halves align and lock tightly without adhesive, the joint can wear in a short period of time. Permanently bonding the wing halves with 30-minute epoxy will secure this critical area for the life of the model.
Only three servos need to be mounted to the airframe; torque-tube–driven ailerons are typical in NMPRA racing. Use metal-gear servos to deliver the solid control needed at high speeds. Control throws are small compared to those of the average sport model—follow the manual's recommendations.
Finish of the Pogo parts, with Hangar 9 UltraCote and paint, is professional. Motor mounting spacers and hardware are provided—smart builders will use threadlock on all metal-to-metal connections. Test the fiberglass cowling for fit and a desired gap between it and the spinner; the cowl needs to be pushed far enough aft to catch the cockpit hatch. Adjust motor spacing as needed for the tight NMPRA look.
The tail wheel is soft wire and bends easily; consider replacing it with a simple wire skid embedded in the tail post.
Power Systems and Performance
- Top speeds:
- Racing Pogo: ~115 mph (uses larger motor, 4S 2500 mAh)
- Sport Pogo: ~80 mph (uses recommended 3S 3300 mAh)
- Weights: both aircraft weigh approximately the same when the sport model uses the recommended 3300 mAh 3S pack.
Both models handle like they're on rails and are a lot of fun to fly. Flight behavior is predictable and smooth thanks to the slippery airframe and thin airfoil, though the slow-flight envelope is faster than that of a conventional sport model. Expect flight times roughly 4 minutes.
Handling, Trimming, and Pilot Tips
- Little trimming was needed around the course to hold a consistent path around the pylons; the recommended CG is perfect.
- A touch of right thrust helped lessen the need for corrective rudder in left-hand knife-edge flight.
- Both sport and race Pogos handled in a similar, friendly manner—sport pilots moving to NMPRA outrunners shouldn't have to relearn how to fly the model.
- During takeoff, expect the Pogo to veer left; counter carefully with rudder. If overly sensitive, add 30%–50% exponential to that control. The narrow gear track contributes to this condition.
- The heavy-duty gear can make it easy to bounce landings. Flight practice helps; switching to a smaller/lighter battery will improve slow-speed handling. A 25C 2200 mAh 3S pack will balance the Pogo and lighten wing loading enough for slower landings.
- A few approach-to-landing stalls at high altitude help the pilot sync with the model's handling.
Recommendations
- Permanently epoxy the wing join for longevity.
- Use metal-gear servos and torque-tube ailerons as specified.
- Use threadlock on motor and metal hardware.
- Consider replacing the soft tail wheel with a wire skid.
- If racing, follow NMPRA-legal power-system rules and approved motors.
Michael Ramsey [email protected] MA
The Idea
"Let's create an electric Pylon Racing event," NMPRA President Scott McAfee proposed at the banquet for the 2008 NMPRA Championship Race in California. The NMPRA has been the official Pylon Racing SIG for the AMA since 1967.
Those gathered were mostly die-hard glow pilots; their initial response to the idea of an electric class wasn't enthusiastic. Scott gathered a small committee to draft rules for size, type, power, and other parameters for a new event. The original committee included Dan Kane, George Parks, John Jennings, Archie Adamisin, Jim Allen, and me (Jerry Small). Others joined as the idea grew.
My responsibility was the airframe: how it would look and how to keep designs equal. Rather than converting current Quickie and Quarter 40 models, we needed an inexpensive, readily available ARF that could be found in hobby shops nationwide. Waiting six months for an expensive molded composite model wouldn't attract newcomers. We needed big players in the hobby industry—Horizon Hobby, Great Planes, Hobby Lobby—to produce simple, light, easy-to-fly EF1 models.
Horizon Hobby was approached first. The company saw potential revenue from a good-looking sport flier that could also be used as a racer; its Sundowner Formula 1 ARF had been successful. Electric Formula One was born.
Gas-engine racers warmed to the idea after seeing and flying prototypes at the 2009 Nats. Horizon Hobby's success with the Pogo has been phenomenal; there have been rumors of other EF1 designs from Horizon, Great Planes (Proud Bird EF1), and Hobby Lobby (Outrageous).
EF1 is becoming a worldwide phenomenon: Canada held its first race with 12 entries and plans more; Robert Van Den Bosch, a former F5D champion, is promoting races in Europe. This could be big—and it's already a lot of fun.
— Jerry Small [email protected]
Sources:
- Electric Formula One rules: http://bit.ly/d0zboh
EF1 Pylon Techniques
The key to smooth, fast flying in EF1—like all RC pylon racing classes—is minimal control throws. Set up your model to take off and fly on low-rate control throws.
Flight and Radio Setup
- Use the entire stick displacement during flight; it may feel uncomfortable at first but pays off when precision and speed are required.
- Many heats are won by flying a larger, smooth pattern around the pylons rather than jerking the racer aggressively around the course.
- Set the radio for high rates during landing, but never exceed the manufacturer's suggested throws. Excessive throw on final can cause tip stalls and cartwheels.
CG and Exponential
- As the CG is moved aft, elevator responsiveness increases, reducing the throw needed for hard turns. Start conservatively and move the CG back gradually.
- Aft CG can make the airplane twitchy—if it becomes impossible to hold steady altitude, you've gone too far.
- Rule of thumb for exponential: maximum of 18% on low rates (negative for Futaba systems, positive for JR/Spektrum radios). Remove all exponential from high rates to improve feel during landings.
Cooling and Power
- EF1 power systems benefit from good cooling. Stand the battery on edge to expose the greatest surface area to airflow inside the fuselage—convective cooling into the airstream is far more efficient than conductive cooling into fuselage materials.
Remember: smooth flying, correct CG, limited exponential, and cooled batteries are part of the winning equation in EF1 racing.
— Aaron "AJ" Seaholm MA RC Pylon Racing Columnist
Transcribed from original scans by AI. Minor OCR errors may remain.
