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| Wingspan: | 91.4 inches |
| Weight: | 40.6 oz. |
| Length: | 50.8 inches |
| Servos: | 4 9-gram servos |
| Transmitter: | JR 11X |
| Receiver: | Spektrum AR7000 |
| Battery: | 3-Cell 2200mAh |
| Motor: | 750kv Outrunner Brushless |
| ESC: | 30A |
| Available From: | Hobby King |
| Price: | $129.99 |
The full size Fox sailplane was introduced in 1993 at the World Glider Aerobatic Championships held in Venlo, Netherlands. The sailplane was designed by Edward Marganski and built in Poland by Marganski & Myslowski. It is a true glider with no motor power. The wingspan is 14 meters or 45.93 feet. Its weight empty is 761 pounds and its stall speed is 53 mph while its top speed is 175 mph. This is not a floater! It is specifically designed for aerobatic competition, at which it has done very well. It is a lovely two seater with a mid-wing and conventional tail. It has fixed undercarriage with two wheels. One under the cockpit and a smaller one at the tail. It is a lovely sailplane on the ground or in the air. The emphasis is on aerobatic maneuvers, at which it excels.
I have flown a non powered Fox sailplane with a fiberglass fuselage and wood sheeted wings at the slope. It was rather heavy and needed moderate wings to comfortably stay aloft. However, when the wind was right she was a blast to fly at the slope. She was great fun for both speed runs and aerobatics in good wind. I have seen one towed aloft at a thermal flying site, and she came down somewhat quickly, but did so as if she was dancing in the sky. My memories of the non powered RC Foxes that I have seen before are very positive.
I was delighted when I was asked if I would like to review HobbyKing's Fox electric sailplane with a 2.32 meter wingspan. If she was anything like the full size or non powered RC versions I have seen before in person or on video she would be a very fun sailplane to fly. I expected she would be capable of good aerobatic maneuvers, and I expected her to be able to thermal in average lift with the motor off. I waited for the Fox to arrive from Hong Kong and was happy to see the large brown box one night when I came home from work. I noticed that my wife had signed for it and there was a sticker on the front that said not to accept it if there was damage to the box. While the box looked great on the top and sides I found the bottom of the box was foam with tape over it. There were four good size holes that had been smashed in the bottom of the box where the foam had been cracked and broken into the box. (The mail person didn't show that side of the box to my wife.) Fearing the worst, I looked into the holes but saw no damage to the Fox. I opened the box and found the Fox had survived her trip from Hong Kong. When I laid out the parts to photograph them I was struck by how much larger HobbyKing's Electric Fox is when compared to another company's electric Fox that I had seen briefly this past fall. It wasn't just the extra wingspan nor the 16 inches for the longer fuselage, it was how much wider and taller the fuselage on mine was compared to the other company's model. I did find one minor problem while unpacking the sailplane: the pilot had come loose in the sealed canopy. Otherwise, the Fox was good to go for final assembly and flying.
The HobbyKing Fox Glider Parts:
I Supplied
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Special Features
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Aileron control internal with control rod running from servo at the wing root. |
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Two bolts lock onto carbon fiber joining rod. |
Elevator control rod is inside the fuselage. |
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Carbon fiber rods molded into the wing. |
Elevator and rudder servos came mounted in the fuselage. |
This proved to be a true ARF. The instructinos stated that it can be assembled in fifteen minutes. I had to do two items of pre-assembly, and then it took me about 35 minutes to assemble and take pictures of the assembly. It's a very easy plane to assemble and set up at the field!
My Fox arrived with the pilot rattling about loose inside the sealed canopy. It was obvious that he was designed to be secured with both glue and two screws. To access him, I carefully cut the glue holding the canopy to the foam cockpit and removed the canopy and then removed the two screws. The glue that was used to secure the pilot was tacky and messy, and I cleaned off the pilot as best I could and then tried to clean the inside of the canopy where I was only partially successful. I mixed up a small patch of epoxy glue and secured the pilot to the floor of the cockpit and then installed the screws through the floor of the canopy and into the bottom of the pilot and set it aside to dry. When I checked an hour later, the pilot was firmly in place. I applied canopy glue to the foam sides and edges that would be in contact with the canopy and put the canopy back over the cockpit. I taped it in place with 14 small strips of masking tape. I set it aside for the night, and the canopy glue dried overnight and was ready to use the next morning. Hopefully, my loose pilot is not a common occurrence.
The other pre-assembly item I did was replace the battery connector that came on the ESC with one that matches my supply of battery packs. This took me about 15 minutes, including getting out my soldering supplies and putting them away when I was finished. By switching to the style of battery connectors that I use I have five 3-cell 2200mAh size battery packs I can use to power my Fox.
The wing came fully assembled in two halves. The wing halves each had two pieces of carbon fiber molded into the wings that could be seen as shading on the underside of the wing. Each wing half had an aileron servo that was located at the wing root. A wire ran out inside the wing and controls the aileron through internal linkage. No external control horn was present to create drag - very pretty design. The wings plugged into the middle of the fuselage and used a carbon fiber rod that fits onto rods molded into each wing half to align, join and secure the wing in place. The molded mid wing mount on the fuselage also helped align the two halves as it was a nice tight fit. A Y-connector was supplied to connect the two aileron servos and allow them to work off of one receiver channel if so desired. Each wing half has two bolts as part of the latching method that tighten onto the carbon fiber control rod to lock the wings together so they stay in place. Assembly at the field just required sliding the wings into the fuselage and tightening the two bolts per side and plugging the servos into the Y-connector connected to the receiver's aileron channel.
Had it not been for my loose pilot there would have been no assembly on the fuselage. The rudder came already in place, hinged, securely attached and internally linked to the installed rudder servo.
The elevator came hinged and attached to the horizontal stabilizer. The instructions talked about gluing the stabilizer in place but it was actually secured to the fuselage with two bolts mounted through the bottom of the fuselage. I did have to install (bolt on) a control horn on the elevator and I did this with two supplied small bolts. I first got the elevator control rod's Z-bend through the second holt on the control horn and with the horizontal stabilizer and elevator mounted in place on the fuselage; I attached the control horn with the supplied screwdriver. In operation the control horn is inside the fuselage and out of sight. Thus all of the gliders control horns and linkage are out of sight. This made for a very pretty sailplane.
I bound a new AR7000 Spektrum receiver to an open model channel on my JR 11X. I connected the servos to it and then glued two small pieces of Velcro into the cockpit where I wanted the receiver and its satellite receiver to be secured. I put the matching Velcro on the bottom of the receiver and the satellite.
There was a molded foam box with a strap in it that was obviously designed for the battery pack. There was some space front and back to allow for minor adjustment of the battery position to hopefully get the proper C/G to balance the plane just using the battery pack. I glued some Velcro in this box to assist the strap in helping to keep the battery packs in place during flights as I already had matching Velcro on my battery packs.
The proper Center of Gravity is critical on a plane but especially so on a sailplane. Balanced ahead of the true Center of Gravity, the sailplane is nose heavy and it does not glide as well, and up elevator has to be used for the plane to fly level with power off in neutral lift conditions. Additionally, the sailplane doesn't respond as well to lift as a properly balanced sailplane on the true Center of Gravity. Balanced behind that point, the sailplane is tail heavy. Slightly tail heavy, she may become more responsive to lift. Too tail heavy, and she can be impossible to control in flight. The instructions gave the C/G point at being 40mm behind the leading edge of the wing. Considering the size of the wing this struck me as being rather forward. (The smaller two meter HobbyKing electric Minimoa pictured below has its C/G given as 54mm behind the leading edge of the wing.) But I started at the recommended 40mm to see how she handled thinking, "Better for her to be nose heavy than tail heavy." Well, I was wrong for doubting! She flies great with C/G at 40mm. I may move her back a few mm with more practice time but she handled wonderfully with the recommended C/G at 40mm.
This is a four channel control sailplane, and I found I used all four controls: throttle, elevator, rudder and ailerons. The rudder has been very useful in correcting for approach on landing, making smooth coordinated turns with the ailerons and in doing various aerobatic maneuvers. It is also helpful in coring turns when I am thermal hunting and think I have found one. The aileron movement was not all that much throw but they are long ailerons, and they performed well helping the Fox execute nice turns and rolls . I recommend that the Fox be flown for the first time at a field that is at least the size of a football field. The Fox doesn't need that much space, but as a pilot, I found I was much more relaxed flying her in a large open area vs. a smaller park. Being calm with a new sailplane or any plane is a good thing.
I like to take several steps forward and make a hard straight forward toss to launch the Fox. I launch with the motor off and turn the motor on when my right hand gets on the transmitter. The Fox glides nicely, and this has worked well for me and for Jeff Hunter. In the video below you will see Jeff Hunter launch with a running start and with the motor off. The Fox, at 2.3 Meters and weighing in at just over two and a half pounds, is a good size sailplane, and a strong toss is highly recommended. Don't try to fly this out of your hand without a good toss. With a good toss and in proper trim there should be no problem.
The video below shows a landing on a dirt infield. Jeff gave full down after touchdown to get the nose down into the dirt to stop her as quickly as possible. On a regular runway she gives a very scale landing with touchdown on the front wheel and roll out on the back and front wheels. She has no flaps or air brakes as sold, and she can have a very scale and long roll out on pavement. She can be brought in and landed on grass but the landings on runways look the best by far. FYI: The front air scoop allowed in a lot of dirt from the infield in the video. I carefully removed the dirt to keep it out of the motor and radio equipment. Jeff and I both felt her descents and landings to be very even and smooth and given the right space she is very fun to land. I have not flown her at a slope site yet much less one with a small landing area. I have no fears about flying her at the Los Banos slope an hour away as it has a nice large landing area behind the slope. I will not be trying to land her in a small space.
In the lousy foggy weather we have been having here in the Big Valley in Northern California I have not really had much of a chance to test out her thermaling ability thus far. I did catch one weak thermal and climbed a couple hundred feet before the thermal drifted out over the Delta, and I flew the Fox back to the field. From that flight and my flying experience I am sure she should do fine when we get to better weather and good lift conditions. She has a nice glide ratio and is very responsive to throttle input and turns per my commands with combined use of ailerons, elevator and rudder. I see no reason why she shouldn't do well in thermal flying and very well in slope flying with a medium breeze. No real place for ballast as she comes so I don't plan to try and fly her in high wind at the slope as I have other heavier scale sailplanes designed to handle big wind conditions.
The full scale Fox is a fast aerobatic sailplane. HobbyKing's Fox is reasonably fast under power and has a fast glide path. She performs very nice loops, inverted flight and split S maneuvers. Her rolls are pretty nice for a large sailplane, too. She does these maneuvers at a good pace and covers a lot of sky very quickly. I found she didn't fly nearly as well if I tried to slow her down from her natural gliding pace, using up elevator trim, and I got much better control and duration letting her fly at her natural somewhat fast glide rate. I hope to practice a full routine of maneuvers this spring when we get better flying weather. Based on what I have tried so far she should do them well.
My long time flying buddy, Jeff Hunter, helped me out with the media for this review. Even though I videotaped his first flight with my Fox he looked like he had been flying her for years. I flew her for some of the still shots taken by my friend Mike in Stockton and I shot some stills while Jeff was flying as well. During my flying I did an intentional climbing stall, and she made a short drop and was back on a nice glide path in moments. Her natural glide speed didn't threaten to allow any stall turns unless I was stupid and tried to fly her too slowly. Her handling was excellent and very predictable. She felt to me like she was flying on rails, and Jeff said pretty much the same thing after his flight. Jeff was very impressed and would have liked to take her home. My video of his flight was much nicer than Mike's video of my flight. I would like to say it was my camera work but the truth is he was smoother on the sticks than I was. I hope you enjoy seeing Jeff's flight with Fox below showing some of the aerobatics she can do.
NO! The Fox has no self recovery to a stabile position if the pilot goes hands off. It continues to go where last directed. This plane is designed for the pilot who has already learned to fly a plane with ailerons. I recommend her to intermediate pilots and better. Pilots with less experience and a pilot they trust can fly this sailplane but should seek help for the first few flights from an experienced sailplane pilot.
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I honestly didn't expect this sailplane to fly THIS nicely! Actually, she was full of nice surprises. First, she looked very much like a scale Fox glider with nice lines on the fuselage and the wing. I have no idea if the airfoil is scale but it performs nicely as she tracks like she is on rails and can both thermal and do pretty smooth sailplane aerobatics. She has a nice climb rate with power on and gave me no difficulty when transitioning between power off and on. Throttle-elevator mixing on my transmitter has made this even easier. With a paved surface landings look extremely scale both on descent and on long roll outs. Despite being made of foam the wings and fuselage seemed sufficiently strong and rigid. The recommended Center of Gravity proved to work very well despite my initial concern. The hidden control surfaces have all worked well, and the servos have handled some power dives and maneuvers performed to test them and the control surfaces. So far I can't think of anything that I would need to change on the Fox. At just under $130.00 I wasn't expecting her to be quite this polished a design and build or this sweet a flier. I hope to report further in the comments section below as we get into the real flying season later this year.
Pluses:
Minuses:
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Actually the long wings of the larger sailplanes make the roll rate slower in general. This is a model of a fully aerobatic sailplane and it does a good job but don't expect rolls like you get with a short wing jet. Do a dive to build up more speed and you will get faster rolls. or into the wind at a slope on a windy day and you will get more speed on your rolls. We were going more for grace than speed in this demo video. My sailplane flying friends that have seen this Fox have all liked it. It tracks very well. Mike H
PS:I too have been surprised by the lack of comments thus far. |
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Latest blog entry: New receiver packs and asking Castle for...
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Dear TurbineFancy:
I long ago learned that we have different definitions for high speed dives. For one person it is a dive of the height from which the plane starts to disappear down to almost ground level when the pull out saves the plane from smashing into terra firma. I have to admit that I have not really stressed this plane very hard yet. Most of my flights were in foggy skies where the fog limited how high I could take the Fox. Checking my notes I have done a 300 foot dive at about 30 degrees out from straight down and she pulled out nicely from that. I would by my nature want to swap out the elevator servo if I was going to try anything more than that or even do that on a steady basis. I have long believed in upgrading the elevator servo especially before trying radical maneuvers. I did get wing flutter on the pull out but honestly I was more concerned about the elevator servo. Sorry I don't have more info for you than that. I don't consider this plane a Hotliner and I am unlikely to push her any harder than I already have on purpose. (But I do on occassion get stupid and try things I know I shouldn't.) I hope that helps a little. Mike H |
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Latest blog entry: New receiver packs and asking Castle for...
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I love that larger FOX. A few other videos of it are online, but this review is clearly thorough—and the video displays a nice flying model. In fact, from what I've seen, other than being bigger it flies no differently than the smaller 1800mm Fox that is available. Yet I would like my Fox bigger!
Now the following is not a critique of the review model. It is a comparison in how, like so many models sold around the world, the same model from apparently the same manufacturer is made differently according to distributors' demands. And this can be frustrating for the consumer. The fist picture is of my 1800mm-span Hype-RC Fox that, along with my Hype Corvalis 400 (aka Flyzone Corvalis 350), I flew the socks off last summer without any problems. It's apparently from the same Chinese manufacturer, hence the same [kit] as the ST-Model Fox. But after reading (and hearing) about some apparent weaknesses with the ST-Model version, I suspect production of the ST-Model Fox may be an "economy" version. A flying buddy in Oregon, smitten after flying my Hype Fox, bought the ST-Model Fox from Tower Hobbies, and he subsequently reported some minor weaknesses. But once corrected (modified) his now flies just fine. Now the larger Foxes: the second picture is of the HobbyFly Fox sold in Germany; the third picture is of the HobbyKing Fox. Except for the rear end of the canopy and including a 1300mAh LiPo battery, the HobbyFly Fox appears exactly like the HobbyKing version. Specifications for both: wing span (2320mm), fuselage length (1290mm), ESC (30A), and even the little pilot figure is the same. But the price? HobbyFly's is EUR €199 or appr. $260 plus postage (w/o radio) from the German warehouse, and HobbyKing's is $120 plus appr. $50 postage. That's a huge price difference. If my observation concerning an "economy" version is correct, I venture to say the difference is in the electronics, primarily the motor—and certainly a 1300mAh LiPo doesn't make up the $140 price difference. So geeze, what could the difference(s) be...if there are any, really? I'd like to know. (Maybe at the upcoming German modeling fairs I can find out.) That said, if I do buy this model, based on this review it will likely be from HobbyKing. I'll glady pay the postage! Thank you for the reivew Micheal.
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I have let a couple friends fly mine and one has ordered one for himself and the other friend wants mine. Mike H
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Latest blog entry: New receiver packs and asking Castle for...
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Finland
Joined Sep 2010
547 Posts
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In the eighties when I was 14-18 I competed quite successfully in FAI free flying gliders. We designed and built the planes from scratch. I also flew some RC planes for fun. I designed one quite good 2.5m non powerd glider. Electric power was more or less non existent in those days because of the technology available. The hobby was buried under motorcycles, cars etc. I flew RC drones when serving in Finnish military in 1990. That was the last time stirring the sticks. I am 100% done with methanol and castor oil.
One year ago I discovered RC helis and the world of brushless motors and lipo batteries. I have always kind of dreamed about a powered glider. I am not into scale planes at all except gliders. They are designed to fly, not just hang in the air with sheer engine power. Like mentioned, I have ordered the HK Fox as my first reborn hobby RC plane. When browsing through the RC forums I also discovered the terms "hotliner" and "warmliner". The opened my eyes. ![]() Long introduction but I already have some plans with the Fox. I will fly it as stock but I plan upgrading the motor with this: http://www.hobbyking.com/hobbyking/s...idProduct=8505 I have one 80A Plush ESC sitting in shelf. The Fox will never be a hotliner. It will never sustain the speeds without wing flutter and explosion mid air. I just plan to make it more powerful for vertical zoom climbs with say less than 10 second bursts. Cruising with gliding or part throttle. What do you think? I know some fuselage mods are needed but cutting some foam and gluing on a new firewall with fibreglass reinforcements cannot be considered very demanding task. |
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