Following in the tradition of the wildly popular Parkzone Habu EDF, Horizon Hobby introduced the Habu 32 DF ARF by E-flite to much fanfare at E-Jets International in 2010. Although they share a similar name and a vaguely similar profile, the comparisons end there. The Habu 32 is in a class by itself and has redefined what is expected in appearance and performance from a moderately priced electric ducted fan sport jet.
"E-flite takes ARF ducted fan performance and engineering to new heights with the Habu 32 DF. Designed around the E-flite Delta-V® 32 80mm fan unit and 2150Kv DF32 brushless motor, its hyper-efficient intake and exhaust ducting allows this potent combo to produce large amounts of thrust when powered with a high-C 6S Li-Po pack. And it does so without resorting to drag-inducing cheater holes. The result is a sport EDF with exhilarating speed that will give even experienced jet jockeys goose bumps."
The Fuselage of the Habu 32 is made from beautifully molded and painted fiberglass that includes the vertical stabilizer. The wings and horizontal stabs are constructed of wood and covered in UltraCote® with precision. The control surfaces come factory hinged with minimal or gap free attachment. Quality components are used throughout with design principles that are integrated into more expensive airframes. When is the last time, or first time, you saw a 350 dollar edf airframe use carbon blade spars for the wing and the stab attachment? never? Beautifully constructed and very effective flaps are also included and optional E-flite retracts are easily added. There are many factory completed steps such as pre-drilled screw holes, factory cut and painted canopy, pre-cut servo control slots, factory mounted servo and battery trays, factory installed intake, etc ...The list goes on and on. All of these factory installed items and completed steps should make for a fairly trouble free build. I couldn't wait to jump in and see what all the hype was about.
|Wing Area:||392 sq. in.|
|Servos:||(7) - JR sport MC-35 servos and a JR DS368BB servo.|
|Battery:||E-flite 6s 5000mah 22.2v Li-Po battery.|
|E-flite 2150Kv DF32 brushless motor.|
|ESC:||E-flite 80-Amp Pro Switch-Mode BEC Brushless ESC (V2).|
|Available From:||Horizon Hobby|
Kit Contents include:
Additional components provided by Horizon Hobby for completion:
I like to read through the manual multiple times before attempting any assembly steps to see if anything is confusing or seems out of sequence. Once again, E-flite provides an exceptional manual that provides clear and concise assembly steps and even provides some extra warnings and tips as well.
The Habu 32 wing panels are constructed of wood and expertly covered with UltraCote from the factory. The horizontal stabilizers are sheeted foam construction and are also expertly covered with UltraCote. The aileron, flap, and elevator control surface are factory UltraCote hinged (The rudder is hinged with hinge points - The rudder is wood although the fin is integrated into the fuselage and is fiberglass). The UltraCote hinge provides for a slop free and gap free control surface. There are also many other small steps that are factory performed which speed along assembly. The wing panels and horizontal stabs are removable on the finished product but before we get there, there are a few construction steps that need to take place first.
First, I needed to epoxy the control horns into factory cut slots in the control surfaces. In order to prevent epoxy slop from contaminating the finished surface, I applied tape as recommended around the opening of the control horn slots before the control horns were glued in. The aileron, flap, rudder, and elevator control horns are installed in the same manner but the elevator control horns are sanded to an angle slightly for proper fit.
in preparation for mounting the servos to the servo covers, I needed to epoxy a set of servo mounting blocks to the back of the main wing panel servo covers. The mounting blocks must be modified slightly to allow the servo wire to clear the block when mounted and then drilled for the servo mounting screws.
The servos are then attached to the blocks with the hardware supplied with the servos. **The manual recommends adding a few drops of CA to the screw holes and blocks to help strengthen the mounting block (CA should also be added to any other screw mounting holes as well for extra strength). I mounted the aileron and flap servo assemblies to the wing with 4 small screws each.
The pushrods for the ailerons and flaps are assembled from 2mm x 25mm threaded rod , two 2mm nuts, two metal clevises and two pieces of tubing (for clevis retainment) cut from a longer piece of included fuel tubing.
The Habu 32 wing spars blades are made from carbon fiber. Before installation, the carbon blades need to be sanded slightly on the glue contact point. Don't skip this step; the un-sanded carbon has a very slick surface which could prove problematic for a solid glue joint. After checking the fit of the spar in the wing and in the aluminum wing socket in the fuselage, I epoxied the spar into the wing according to the manual (follow tips in the manual for keeping the wings from being glued to the fuse).
Although the installation of retracts is considered optional, I consider them mandatory on an airframe like this. Even though the E-flite retracts come with their own struts, they are not used with the Habu 32. The struts that are provided in the Habu 32 kit box are used and are sized and bent perfectly for the airframe and the retracts.
The covering over the retract mounts and wheel well openings must be cut away prior to retract installation. After cutting the covering, I placed the retract mechanisms on the gear rails and drilled them for the mounting screws (remember to back the screws out and add a few drops of CA to the holes). Next, I substituted the Habu 32 kits struts in the retract units and installed the assemblies in the wing panels.
The stock wheels are made with an aluminum hub and look great. The only not so great thing about the wheels comes when it is time to insert the plastic bushings. The bushing themselves fit on the axles just fine but when I inserted them into the wheels they compressed and no longer fit the axles properly. It took a little coaxing with a drill bit to get the wheels and bushing spinning freely on the axles.
The optional (again, not really - unless you are flying from grass) retract gear doors are made from a piece of thick plastic that is painted to match. As noted in the manual, I bent the gear door slightly to shape to cover the gear strut and still lay flat on the edges of the wheel opening. Don't get too carried away here while bending the door. It will begin to crack the paint and split the plastic if bent too far. The gear doors are mounted with wood mounting blocks (I had to sand the blocks to shape first) and four screws to the struts.
I will admit I was thrilled to see how easy the nose gear retracts and steering servo would be to install. I have built a number of kits where the steering servo and nose gear seemed like an afterthought ... often with servo in very hard or impossible to reach places after final installation.
Once again, I needed to swap the provided fixed gear strut with the one on the retract unit. I installed the steering servo with 4 wood screws in the tray directly behind the retract mount. The retract unit is installed with 4 screws into the retract mount. Another nice touch; the blind nuts for the retract screws are factory installed.
After I installed the nose gear wheel and retracted it for the first time, I noticed that the wheel hung down past the nose gear cover ever so slightly. I wanted the wheel to be completely inside of the fuselage when retracted so I bent the strut back a little.
The rudder servo is a press fit into a set of mounting blocks that are located in the side of the vertical fin. The spacing on the mounting blocks on my kit were a little too close together and kept the servo from sliding in freely. I used my Exacto knife to slice away a little of the wood on the mounting blocks. After this slight modification, the rudder servo fit perfectly. The rudder servo is then held in place with a plastic "Servo strap". The entire assembly is covered with a servo cover that is held in place with tape.
As designed, the horizontal stabs are removable. Like the main wing panels, the stabs also have a carbon spar attachment system although they are held in place with screws through the spar instead of a pressure fit from screws.
Before the spars could be epoxied into the horizontal stabs I needed to sand the spars along the contact surface where they fit into the stabs. The spars are then epoxied into the horizontal stab and mounted on the fuse for proper fit while they dry (follow tips in the manual for keeping the stabs from being glued to the fuse). Two screws are used for each spar to attach it to the former.
The elevator servos are mounted on pre-installed servo trays that are located on the side of the fan intake. All I needed to do was secure the servos with their mounting hardware and prepare the elevator pushrod tube supports.
I constructed the elevator pushrod supports from three separate plywood pieces. These supports are then screwed into support trays in the fuselage while passing the pushrod housing through them. The pushrods, clevises, retaining nuts, and silicone tubing pieces are added to complete the control rods between the servos and the elevator control horns.
I mounted the motor to the fan unit according to the directions using screws and thread locker for extra security. Make sure to pay attention while installing the motor and fan fairing as there is a top and bottom of the fan shroud.
I did a quick test fit of my assembled fan unit and found that it did not fit into the fiberglass intake. I used my Dremel tool and rotary drum to grind away a little excess epoxy to achieve proper fit.
The thrust tube is factory assembled but I needed to notch out part of it where the fan fairing will pass through at final installation.
The assembled fan unit is passed through the hatch on the bottom of the fuselage, pushed into the fiberglass intakes, and secured to the mounting tray with four screws (I needed to temporarily loosen the previously installed pushrod guides to allow the fan to be inserted properly). After the fan unit was installed, I slid the exhaust tube (must be partially folded first) up the rear of the fuselage and attached it to the fan shroud with tape.
I followed the manual for the basic radio receiver layout. I did however need to undo a few of the previously installed extensions and move them around slightly to make it easier to get the connections to their proper locations in the fuselage wing saddle.
Now that I had the connections for my main gear, flaps, and ailerons routed to the wing saddle I could move forward and attach the wing panels. With the servo connections made, I slid the carbon wing spars into the aluminum fuselage spar sockets and tightened them down with the socket head bolts. The left wing panel fit perfectly but I now noticed a slight gap at the front edge of the right wing panel where the leading edge meets the fuselage. In order to fix this slight leading edge gap, I made a CA ring around the rearward anti-rotation pin socket on the fuselage. This forces the rear of the wing outward slightly which pushes the leading edge up against the fuselage.
Before being inserted into the canopy, I cut the cockpit interior to shape. Next, I installed a Parkzone T-28 pilot that was provided by Horizon Hobby (The pilot is just slightly tall and contacts the canopy when installed without modification. I eventually trimmed the pilot slightly for better fit). The canopy itself is factory assembled and includes a wood frame that has two locating pins at the front and a hole to accept the fuselage latch at the back. The cockpit interior is held in place inside of the canopy frame with tape.
Until this point, I had been using generic settings in my radio for the programming just to make sure the servos were centered and moving in the right directions. While looking up some technical specs on the Horizon Hobby website for the Habu 32 I noticed a download file for the DX8. This was too easy to pass up! The only thing I added to the download settings was a trim for the steering so I could adjust it by itself.
With The Habu 32 upside down on my balancer I found that it needed absolutely no extra weight to balance at 115mm with the battery at the front edge of the battery tray.
Now that the Habu 32 was programmed and balanced, I wanted to see exactly how much power I would be dealing with. I hooked the Habu 32 up to my wattmeter for some readings. Five seconds into a run with a fully charged battery I was seeing 1457 watts at 65.4 amps. That's about 200 watts per pound. That should be plenty of power for jet like performance.
Although I have heard of many successful flights of Habu 32s from grass surfaces, all of my flights to date have been off of pavement; Our grass field just isn’t short enough for the small wheels on the Habu 32.
While taxiing out for the maiden takeoff it was quickly obvious that the Habu 32 rolls very well. I made a mental note to try to land the Habu 32 at the front end of the runway in anticipation of a long rollout after touchdown. As mentioned earlier, I downloaded the Habu 32 file for my DX8 from the Horizon Hobby website. The download included control rates that are set up for 3 positions. For the maiden flight I had all of my control surfaces in the mid-rate setting as recommended in the manual. After taxiing the Habu 32 on the mid-rate setting for maybe 100 feet, I decided to switch the steering / rudder over to the low rate setting. The low provides for positive control without being overly sensitive … the steering becomes a little too sensitive for my taste on the other settings. For the first flight I left the flap up as recommended. I began the takeoff roll by slowly feeding in the throttle to get a feel for the steering under power. After I was comfortable with my heading down the runway, I simply advanced the throttle and slowly began to feed in up elevator after I thought would be flying speed. The Habu 32 responded with a very mild lift off and moderate climb (I was happy to see the nice gently liftoff. I have had a few runway leapers and those can be nerve racking). At the point of lift off I was at about ¾ throttle. I reduce the throttle slightly to trim the model. The Habu 32 only needed a few clicks of right aileron and a few clicks of up to fly level hands off.
Subsequent takeoffs were tried at the mid flap and no flap setting. I prefer the no flap takeoffs. Without flaps, the Habu 32 lifts off of the ground gently with a slightly nose high attitude and climbs with the front of the airframe. The no flap takeoffs also seem to be more predictable in gauging when liftoff will take place. In the mid flap setting, The Habu32 lifts off of the ground and tends to rise up vertically with the fuselage parallel to the horizon. It is also possible to experience a slight wheel barrel effect (The main gear will lift off first with the nose gear still on the ground) if you don’t hold enough up elevator while taking off with flaps. Gauging liftoff is a little harder with flaps although not too difficult that it will catch you off guard.
Landing the Habu 32 has proven to be a rather stress free event depending on how I set up my approach and what flap setting I use. On my maiden flight I decided to land on the low rate flap setting since there was a moderate breeze heading down the runway. First, I made sure all of the landing gear were in the down position. I set up my glide slope a little higher than I normally would given the breeze and the mid flap setting I was on. I didn’t want the wind to slow the Habu 32 down too much so I stayed away from the high rate flap setting. I slowly backed off the throttle and added some up elevator as I settled in on a moderate glide path. Although the mid flap setting did slow the airframe down some and provide some extra lift for slow flight, it wasn’t quite what I was hoping for and the Habu came in a little quicker than I wanted. When I set the airframe on the runway I hit a crack on the tarmac and it bounced back into the air. I set the Habu 32 back down gently on the runway with a little more elevator input and made my final landing. My mental note from earlier was a non-factor. Even though I landed going a little fast, the Habu 32 didn’t feel like it rolled out an unreasonable distance. The Habu 32 is a fairly slick airframe. It was apparent after the maiden landing that a moderate breeze isn’t going to slow this airframe down too much.
Subsequent landings were tried at full and mid flap settings. I prefer the full flap landing in all situations except heavy winds (The Habu 32 slows down quickly in heavy winds on full flaps). In heavy winds I prefer the mid flap setting. On the full flap setting, the Habu 32 slows down nicely and is easily kept in a stable shallow glide path as long as the throttle is manipulated properly to adjust for landing speed. Surprising little elevator input is necessary (until final flair) once you are set in the final landing pattern on full flap. If you chop the throttle on a shallow glide path on the full flap setting the Habu 32 will slow down quickly which could result in a stall. Although chopping the throttle and gliding in for landing can work on full flaps on a steeper glide slope, the landings are much more consistent with the throttle management system. Smooth Landings on mid flap are possible in any condition but it is a bit trickier to get that nice final touchdown. In the mid flap setting I needed to hold the airframe off on final flair for a much longer period. Landing speed is higher so make sure not to land going too fast or you could be rewarded with the dreaded kangaroo jet hop landing. A somewhat shallow glide slope, proper throttle manipulation, smooth elevator movement, and a final flair are the keys to getting nice smooth landings with the Habu 32. Once you get the feel for it, you will be rewarded with smooth landings almost every time. Having said all of that, it is easier than it sounds.
The Habu 32 is a slippery airframe and what I noticed very quickly is how well it retains energy during its flight envelope. This is a performance edf airframe and once the landing gear and flaps are pulled up it's on! The recommended power system provides for very quick and powerful flight. I routinely average speed passed of 125mph in slight dives. In large dives, passes of 150mph or more are easily achieved. Vertical performance is very impressive especially after a nice speed pass. I am sure you have heard this before but this airframe flies very smooth and tracks like it is on rails. It has positive control input in all axis and I never get the impression that I am on the verge of losing control…at least not while on low rates. I personally like my jets to fly smooth and precise and I find the recommended low rates (except for rudder) to be the only setting I need (I only flip to high rate for an infrequent snap or flap spin – sometimes you have to put on a show). For me, the high rate settings introduce a control surface sensitivity that can cause one to over control the airframe. Although high speed flight truly shows off the capability of this airframe, The Habu 32 also excels at slower flight. The Habu 32 looks great on a dirty flyby with the gear and flaps fully extended.
The Habu 32 has very different stall characteristics depending on the flap setting. Without any flap deployed the Habu 32 stalled a little slower than I was expecting but it still had decent forward momentum. The stall happened pretty quickly and the airframe usually fell off to one side or the other (usually right). Recovery was very simple with power and elevator input but it does take a bit of airspace to recover from … don’t try this at low level. On the medium flap setting the stall is gentler and happens at a slower airspeed but there was usually still a slight fall off to one side or the other. On the high rate flap setting the Habu 32 stall is almost a non-event. The stall happens at what seem like just before all forward momentum stops. The Stall is very gentle and in fact the stall is very similar to what I experienced when flying RC canard airframes. Instead of falling off, the nose just drops forward and starts to bob up and down as airspeed is regained. Recovering from the high rate flap stall is very easy with a little power and a little up elevator.
The Habu 32 will easily perform basic flight aerobatics that most scale jets are capable of. Given the Habu 32’s more than adequate power and its energy retention, the basic maneuvers are executed easily. Rolls are axial and require very little down elevator when inverted to maintain a horizontal flight path. Sustained inverted flight is easily achieved with a minimal amount of down elevator. While inverted, control is still easily maintained. The Habu 32 flies very well inverted, in fact it flies as well upside down as it does right side up (much like the Parkzone Habu). I find myself flying this airframe upside down very often. Loops can be rather large and gracefully as long as power is carried properly throughout the upside of the maneuver. On medium or high rate rudder, the Habu 32 performs some very graceful stall turns. There is a little tail waggle coming out of the maneuver but I have been able to correct it slightly by letting of off the rudder earlier in the turn. Given the smooth flying characteristics, the Habu 32 handles immelman turns, Cuban eights, half reverse Cuban eights and the like very well.
Since the response on the control surfaces is rather crisp, the Habu 32 performs some rather impressive point rolls. I can usually get them to come out how I want them as long as I lead the stop on the knife edge points with a little rudder. The rudder is rather effective but in order to maintain level knife edge flight a high rate rudder setting and a high rate of speed is necessary. Without correction the Habu will pull a little to the canopy on knife edge. The Habu 32 will also perform some graceful snap rolls on low rate. On higher rate the snaps can become a little violent and can sometimes end in a short flat spin. My favorite combo of maneuvers is to come down on the deck after a huge dive and pull straight up to vertical rolling the whole time. At the top I pull out and come back for another dive and do point rolls along the edge of the runway ... exhilarating! If you have seen it with a scale jet you can probably do it with the Habu 32.
This is not your daddy's Parkzone Habu. This is a much higher performance airframe that can bite you if you are not careful. The higher wing loading might present some issues for those wanting to get into higher performance jets but are used to flying airframes that land slowly. I would think that a modeler who has mastered a high speed sport plane with a higher wing loading could handle the Habu 32.
Most of the current generation EDF jets fly well enough; unfortunately, many in this class don't fly with the level of performance and precision seen in the Habu 32. This is what sets the Habu 32 apart from the others in this class and even beyond. Does it fly like a top of the line 5000 dollar composite airframe? Well, maybe not exactly but it is not too far off! It is closer than anything else I have flown to date. The Habu 32 does indeed take some of its construction techniques from those higher priced airframes (carbon blade spar retention system, sealed control surfaces, bottom hinged flap, etc…) while keeping the cost at a much more reasonable level.
It was my hope that the Habu 32 would be that everyday performance edf jet that I could toss in the back of the SUV in one piece and head to the field. It has been that and more. E-flite claims in their advertising the Habu 32 … “is a sport EDF with exhilarating speed that will give even experienced jet jockeys goose bumps”. It is obvious the creative minds behind the Habu 32 had performance, precision, and great flying characteristics as their final goal … and they hit the mark, goose bumps included!
More paint options or an all-white (or solid color) version.
***Special thanks to Ken Park for the inflight photos, Matt Finley and Kirk Sonnier for video, Jack Fetter for the open animation for the video, and Horizon Hobby for the opportunity to review the Habu 32!
|Nov 18, 2011, 08:54 AM|
Excellent Work Kevin - Koodoo's and two thumbs up!
Was that me standing next too you in bright oranage E-Jets T-shirt in the video? eeek!
PS: My camera is so good it even picks up your thoughts at Ejets 2011
|Nov 18, 2011, 10:19 AM|
Very good review, on a superb model airplane.
HH (E-Flite) certainly produced one of the highest quality/value products ever offered to the hobby with this jet.
My Habu 32 takes off from grass fields (not super smooth, but reasonably smooth) with and without half-flaps; half-flaps are shorter and easier for me.
Definitely needs full flaps for landing in light winds.
After a full throttle pass, it's better to reduce throttle and climb vertical, rather than simply reducing throttle to turn; it just moves too fast and goes too far.
|Nov 18, 2011, 10:31 AM|
You are lucky you didn't post that picture before I maidened your plane j/k
Thanks guys. I am really liking the habu. It always goes to the field...
|Nov 18, 2011, 11:55 AM|
Photo Removed! Kevin
Ok I won't send that one into the magazines! Since I still need your help next year at Ejets. Thanks Kevin your still the man.
|Nov 18, 2011, 01:06 PM|
|Nov 18, 2011, 01:49 PM|
Ok! glad we can all get a giggle!
I'll get the photo back up on Monday - Gota shut things down now for the weekend - Its Miller time!
|Nov 18, 2011, 01:59 PM|
Maybe that's the problem. I have never had a cup of coffee...last time I checked it was bean water and I'm just not that interested in that.
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