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Written by Josh Bernstein
Hone your 3D skills day or night
Product Review
As seen in the April 2018 issue of
Model Aviation.



Bonus Video


Specifications

Model type: Electric 3D/aerobatic
Skill level: Intermediate to advanced pilots
Wingspan: 60.2 inches
Wing area: 792 square inches
Length: 58.2 inches
Wing loading: 18 ounces per square inch
Cube loading: 7.7
Weight: 99 ounces
Power system: Brushless electric outrunner
Radio: Spektrum DX6
Construction: EPO foam with carbon-fiber supports and plywood subframing
Price: $499.99; $449.99 without lights


Test-Model Details

Motor used: Potenza 60 3D 500 Kv brushless outrunner
Speed controller: Hobbywing Skywalker 80-amp ESC with HV 8-amp external SBEC
Battery: Glacier 6S 45C 4,000 mAh
Propeller: 16 x 6 custom-tooled Somenzini-Ribbe (SR)
Receiver: Two Spektrum DSM2 Satellite
Servos: Four Potenza DS33HV digital metal-gear servos
Ready-to-fly weight: 110 ounces
Flight duration: 5 to 12 minutes (depending on battery choice)


Pluses

• Lightweight, rigid, durable EPO foam with a plywood/carbon-fiber substructure.
• Wide flight envelope includes sport, precision, and 3D.
• Aura 8 Advanced Flight Control System provides stability and refinement.
• Couple-free, knife-edge flight out of the box.
• Simple assembly process—from unboxing to flying in roughly an hour.


Minus

• Trim changes must be made in conjunction with the Aura 8 flight control system, requiring a few extra steps during the initial flight.




With ample power and stability, the QQ CAP’s hovering mannerisms inspire confidence.



Product Review

Go to any online RC forum and search for CAP 232 and you’ll be inundated with threads discussing this iconic airplane. Loved by many, this low-wing, aerobatic airplane was scaled from the CAP series of aerobatic aircraft, which dates back to Claude Piel’s CP.30 Emeraude in the early 1960s (eventually becoming the full-scale Mudry CAP 230/231/232).

As airframes go, the CAP 232 has always been thought of as more of a “scale aerobatic” platform. With the increased availability of a midwing, pure 3D machine, the CAP airframe has fallen out of favor with some aerobatic fliers. The wing and stabilizer placement on a CAP can result in some unique flight characteristics, although many of these issues can be mitigated during setup. As any CAP enthusiast will tell you, proper setup on a CAP is mandatory.

For Flex Innovations to choose to release a 3D CAP model in the current climate shows an impressive level of confidence. Considering that Quique Somenzini (QQ) is part of Flex Innovations, that confidence is well founded.

Flex Innovations has an impressive team of industry veterans, a great reputation, and a solid fan base. I am impressed with the company’s ability to take such an iconic airframe and make it perform so well. Tweaking and reengineering an old-school design then marrying it to modern technology results in a CAP 232EX with almost none of the challenges present in the original design.

Flex Innovations considers the QQ CAP as the perfect next step after its QQ Extra 300 and Mamba 10 aerobatic airplanes. With a wingspan slightly more than 60 inches, a length of 58.2 inches, and weighing nearly 7 pounds, this is not your everyday foamie. With nearly 800 square inches of wing area, it is big for the 60-inch class of aerobats, yet it’s easily broken down and transported with the wings off. Plus, adding a few extra 6S 3,500 LiPo battery packs won’t break the bank.

Although the build process is straightforward, I have listed a few points online and in the digital edition that deserve extra attention.

Foam models sold as Plug-N-Play (PNP) often include subpar components. Although considered a cost-savings technique, many decent airframes have been brought low by an undersized or poor-quality motor, ESC, and/or servo set. Flex Innovations’ design team has turned this paradigm on its head. The QQ CAP 232EX comes equipped with solid components.




The QQ CAP arrives with its components installed and the control surfaces prehinged, allowing the pilot to go from unboxing to flying in roughly an hour.


A Potenza 60 3D motor is mated to a Hobbywing SkyWalker 80-amp ESC with an external 8-amp switch-mode battery eliminator circuit (SBEC). This provides plenty of power to the Potenza digital/metal-geared/high-voltage (HV) servos.

Including the HV servos and an external SBEC shows how seriously the company takes its customers’ needs. The HV servos provide extra torque and speed, and the external SBEC allows pilots to maintain control over the airplane should the ESC fail. Generally, both are only found on higher-end models.




Combining digital/metal-geared/HV servos with bilateral ball links results in fast and powerful control-surface deflections with minimal slop.



Construction

The airplane arrived tightly packed, with each part separated and supported. The QQ CAP 232EX is sold only in a Super PNP configuration with either a blue or yellow scheme. The manual suggests a 1-hour build time.

For those who prefer to fly in the early mornings, heavy fog, or late evenings, a Night version is available with an array of LED lights built into the airframe. The lights can be powered from the main 6S battery pack (using the included balance lead) or from a small 3S battery pack. Although this review covers the Night version, the build process and programming steps for the Standard version are identical.




The optional Night version has LED lights running throughout the airframe, allowing for nighttime and early morning flying.


The manual provides clear instructions on programming your transmitter and walks you through the Aura 8 AFCS setup. According to Flex Innovations, the Aura 8 is compatible with “virtually every receiver on the market today.” I opted to take advantage of this flexibility by utilizing a pair of simple Spektrum DSM2 satellite receivers (full-range receivers without ports).




The Aura 8 AFCS is compatible with a number of radio systems. It is preloaded with all of the necessary programming, simplifying radio setup


Having eight channel ports (and advanced programming and mixing capabilities), the Aura 8 can manage all of your servo connections, allowing a satellite receiver’s digital connector and a six-channel radio to control the system.

A major selling point of the QQ CAP 232EX is the fact that all programming is done at the factory, requiring minimal radio setup. With all of the rates and exponential settings, coupling mixes, stabilization gains, and flight modes preset in the Aura 8, after you’ve installed your receiver you can get right to flying.

Using a PC-based computer or tablet and the supplied USB cable, the Aura 8 allows users to customize a wide range of parameters. Although customization is nearly limitless, most users will choose between the Stock and the Expert flight mode setups. Each flight mode includes a specific combination of rate, exponential, and stabilization gain.

Particularly for a more skilled 3D pilot, it is well worth the small amount of effort required to select the Expert flight mode setup. Having spent countless hours flying my Flex Innovations Mamba 10 biplane, which utilizes a similar flight mode setup, I can speak to the benefit of having a low- and high-speed 3D mode.

The two 3D modes have distinct rate and stabilization gain settings that maximize the different styles of 3D flight. Post-stall maneuvers (harriers and hovers) feel more stable and locked-in, and high-energy tumbling maneuvers, which often require high-speed entries, are maximized. Switching to the Expert flight mode setup should be done after all linkages are connected. Being able to turn the stabilization off (stock flight mode 1) is useful during assembly.

Regarding the Aura 8, some traditional pilots, accustomed to having near dictator-level control over their model’s setup and radio programming, might be turned off by these advanced stabilization systems. However, with more manufacturers releasing models that utilize programmable stabilization, and with the benefits such systems can bring, I think it’s good to develop some comfort with the available technologies.

The QQ CAP 232EX is an advanced 3D/aerobatic airplane. It is marketed toward intermediate and advanced pilots who are looking to improve their skills. (After performing a “Quick-Trim” process following the maiden flight, no additional programming changes were required. All rates, exponential settings, and coupling mixes were spot-on.)

The manual recommends balancing the model fully loaded, under the wing in an upright orientation that is 105mm aft of the rearmost side of the landing gear slot. The generous battery tray allows for some adjustment depending upon the battery size, and I found that I was able to achieve this initial center of gravity (CG) with a range of LiPo battery packs.

The battery tray is generous, but the removable canopy is massive. After it is removed, there is total access, easing assembly, battery switches, and receiver setup.




The generous battery tray allows easy access for a range of battery packs, providing flight times from 5 to 12 minutes.

I like to bench-test aircraft to confirm that the power system is working correctly, determine the model’s power-to-weight ratio, and test the battery packs to be used during flight testing. With a reasonably new Glacier 6S 4,000 mAh 45C LiPo battery pack, the motor pulled 60 amps, or slightly less than 1,400 watts, resulting in approximately 200 watts per pound.

On 3D models, power is nice, but thrust is king. With the low-pitch, custom-tooled propeller humming at full throttle, I could barely keep the model from turning my living room into its maiden flying site.


Flying

After range-testing, servo deflection checks, and confirming the CG and propeller tightness, I selected Expert Flight Mode 1 (sport/precision) and taxied the QQ CAP to the runway. I brought power up to roughly half and rotated the airplane off of the runway in a scalelike manner. Leveling off and reducing throttle to half, I began my standard in-flight testing by trimming the airplane to fly straight and level upright.

Most stabilization systems require you to reset the trims to neutral and mechanically adjust your control surfaces after trimming. This avoids a trim-shift issue when switching flight modes. The Aura 8 has a Quick-Trim feature that allows users to handle this process electronically, negating the need to disconnect and adjust multiple linkages.

With trimming complete, I rolled the airplane inverted to get a sense of its CG. With my 590-gram, 4,000 mAh 6S battery pack centered between the two battery straps, the QQ CAP required only a breath of pressure on the elevator stick to maintain level, inverted flight. Slightly nose-heavy is the sweet spot for 3D/aerobatic flight, resulting in a good balance of 3D, precision, and balloon-free landings.

I spent a few minutes flying gentle sport patterns, both upright and inverted, with an occasional stall turn or Immelmann. The model performed these mild-mannered maneuvers beautifully, but it felt like driving a Porsche in stop-and-go traffic.

I rolled the model into a knife-edge orientation with virtually no coupling present, and the QQ CAP tracked straight and true.

I spent the next minute or so flying knife-edge ovals and Figure Eights, impressed with how locked-in the model felt, whether at speed or moving slowly in a high angle-of-attack. Snaps and rolls were crisp and precise. I was able to perform clean point rolls and slow rolls to my heart’s content.

Eager to see what this 3D machine was capable of, I lined up on the runway, reduced throttle, and slid the model in for a scale landing. There is no need to discuss this airplane’s landing mannerisms. Fly it in at 1/4 throttle and it’s ridiculously docile.

Flex Innovations suggests a range of 5- to 12-minute flight times, depending on the battery size. I experimented with different batteries and found this to be true.

Starting with a fresh battery pack, I selected Flight Mode 2 (high-speed 3D mode) and launched the QQ CAP skyward with a full-throttle takeoff. Tremendous vertical performance had the model 100 feet high in seconds. I reduced power and floated the model down in a flat spin for some post-stall testing.

The CAP airframe is considered to be stable during inverted harriers because the tail surfaces hang down in clean, undisturbed airflow. On the other hand, upright harriers (with its wing set lower on the fuselage) have historically been a dicey proposition. Again, the design team at Flex Innovations has sprinkled its magic dust. The QQ CAP is as stable in harriers as any airplane that I’ve flown.

Regarding the QQ CAP’s hovering characteristics, I’m at a loss for superlatives. It is truly remarkable. With more than enough power to blast out of danger and with such well-mannered composure and stability, the model seems content to simply hang nose-high a few feet off the ground for as long as you’d like.

After temporarily getting my fill of post-stall testing, I landed the QQ CAP, switched out batteries, and again selected Flight Mode 2. Bringing the model off the ground with speed, I entered the flying field with full throttle and performed one of my favorite maneuvers: the pop-top.

Combining power, energy, and a hint of gracefulness, the pop-top is a good maneuver to test multiple aspects of an aerobatic model’s mannerisms. The QQ CAP didn’t disappoint, and I continued aggressive testing with a range of violent tumbles, culminating in the wildly popular knife-edge spin.

The Aura 8’s factory settings (and recent firmware upgrades) result in the system providing a near-perfect balance of assistance, without interfering during more advanced maneuvers.

The LED lighting system brings a whole new aspect to flying. The lights are bright enough that complete darkness isn’t necessary to experience the effect. Early morning fog provides a great atmosphere to utilize the feature, and there were several mornings with the QQ CAP where fog kept all other airplanes grounded.

Of course, there’s nothing like flying the QQ CAP 232EX Night version at night. With LED strips running the length of the fuselage and throughout both the wing and stabilizer, the entire airframe is illuminated.

A well-designed 3D/aerobatic model should have a flight envelope that covers the three fundamental cornerstones of 3D/aerobatic flight: precision, post-stall, and extreme aerobatics. I’ve flown airplanes that are incredibly precise and tumble like mad, but when I bring them in for some low-and-slow fun, they are annoyingly unstable. I’ve flown airplanes that are great tumblers and a joy to harrier, but coupling is terrible and precision tracking is horrid.

Although I might occasionally bring such an airplane to the field, it will never be my go-to aircraft. The QQ CAP 232EX provides solid performance in each area. Additionally, based in no small part on its massive wing area, this model can feel downright floaty.


Features:

Highly engineered and designed, the model includes several features of note:

“Shark’s tooth” vortex generators at the wings’ leading edges reenergize the airflow, improving slow-speed control and reducing tip stalls.

The Aura 8 Advanced Flight Control System (AFCS) manages flight modes, mixes out coupling, decreases wing rock, and can be mated to a simple satellite receiver for full-range flying with a six-channel radio. Firmware updates allow for increased stabilization while reducing “bounce-back” effect.

A plywood substructure and carbon-fiber wing and fuselage supports, increase rigidity while keeping weight in check.

Massive prehinged control surfaces, combined with moderate wing loading and ample power, offers true 3D capability.

Four fast and powerful, preinstalled, high-voltage, digital metal-geared servos require no linkage assembly.

Ball links utilized at both servo and control horn for slop-free operation.

Capable of flying with battery packs ranging from 5S 2,800 mAh to 6S 5,200 mAh.

The stylized sticker package is a welcome substitute for paint options found on many foam models.

Instead of an all-inclusive bag of parts, specifically labeled bags contain only the parts needed for each step, simplifying and speeding the build process.




Maintaining its iconic shape, the Flex Innovations QQ CAP pays homage to history, while embracing technical innovation and progress.


The Build Process

Although the build process is straightforward, a few points deserve extra attention:

Before installing the rudder and elevator linkages, confirm that the servo arms are perpendicular to the servo cases. Do this by turning on your radio, switching your CH5 (gear) to the Mode 1 (gyro off) position, and power on the model. (Wiggle the airframe to confirm no stabilization.) The servo arms and linkages (except at the elevator control horn) can now be installed.

The rudder is prehinged at the factory to a small section of the vertical fin, which is attached to a corresponding section of the fin with medium CA glue or epoxy. A lower, plastic hinge piece is mounted to the fuselage with a self-tapping screw. This screw shouldn’t be tightened completely because some play is necessary for bind-free hinge movement.

When a model is shipped with CA hinges preinstalled in foam, it’s a good idea to tug on all of the control surfaces to confirm proper retention. I found two places where some additional CA adhesive was necessary. I fully deflected the surface and dripped some thin CA on the hinges.

When installing the stabilizer/elevator halves, be patient and gentle. The halves slide into tight plastic receivers. This is a good because rigid tail section benefits flight performance, but forcing the fit during assembly could result in damaging your new airplane.


The Stock Setup and Expert Setup

Stock Setup:

• Flight Mode 1: Gyro off. Sport/precision rates, low exponential.
• Flight Mode 2: Sport mode. Sport/precision rates, low exponential, low gains.
• Flight Mode 3: 3D mode. High rates, moderate expo, high gains.

Expert Setup:

• Flight Mode 1: Sport mode. Sport/precision rates, low exponential, low gains.
• Flight Mode 2: High-speed, 3D mode. “For half to full throttle … ideal for tumbling and high-energy aerobatics.” Rates and exponential are high, low gains.
• Flight Mode 3: Low-speed 3D mode. “Ideal for harriers, hovering, and other slow speed flight.” Rates are maximized and exponential is high. Highest gains. (“As the gains are at their highest, control surface oscillation may occur at high speeds which may lead to a potential crash.”)


Conclusion

Smooth and stable when I wanted it to be, aggressive and violent when I wanted it to be, precise and crisp … Well, you get the point. It usually takes me a dozen or so flights to fall in love with an airplane, but after just a few flights with the QQ CAP 232EX, I was on my knees proposing. This model represents a blend of a well-engineered airframe capable of extreme 3D performance with an advanced flight control system that smooths any rough edges. It provides a comfortable flight experience, and does so with a light touch to allow the pilot to maintain a feeling of direct connection with the airplane. Considering its aesthetic appeal, power, precision, stability, tumbling abilities, durability, and general width of flight envelope, the QQ CAP 232EX is a game changer.





—Josh Bernstein
joshbernstein2@yahoo.com


Manufacturer/Distributor:

Flex Innovations/Premier Aircraft
(866) 310-3539
www.flexinnovations.com


Sources:

Spektrum
(800) 338-4639
www.horizonhobby.com

Potenza
(866) 310-3539
www.flexinnovations.com






2 comments

Thanks for the comprehensive review. That wing loading spec? Something seems off there. Thanks,
ned

Looking a bit more at that wing loading number, it seems it should be 18 oz per square foot (without the battery weight).
ned

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