Sawn Craft Micro F-4D/F-6 Skyray
|Wing Area:||73.75 sq in (4.76 sq dm)|
|Flying Weight:||1.25 oz (34g)|
|Construction:||CNC-milled EPS sheet foam; carbon fiber fuselage spar; carbon fiber, piano wire and shrink wrap pushrods; laser-cut lite ply control horns|
|Control Board:||ParkZone PKZ3352 DSM2 receiver/servo/ESC combination|
|Transmitter:||OrangeRx T-SIX 2.4GHz six-channel computerized spread spectrum aircraft|
|Propeller:||E-flite EFL9051 130x70mm|
|Battery:||Lectron Pro 180mAh 3.7V 45C lithium polymer|
|Motor/Gearbox:||ParkZone PKZ3616 Ultra Micro P-51 replacement motor; HobbyZone HBZ4929 Ultra Micro Champ replacement gearbox|
|Operator Skill Level/Age:||Experienced beginner/intermediate; 14+|
|Manufacturer:||Sawn Craft, Granby, Connecticut USA|
|Price (USD):||$24.99 with free shipping|
The proliferation of micro-sized, easy-to-fly RTF models in recent years has led to an equally interesting proliferation.
Many of those models have been crashed, repaired, crashed again and possibly forgotten by their owners. Or, they're simply gathering dust after their owners moved on to larger, more complex models.
That equally interesting proliferation is that of scratch built models and even kits based on the electronics and that's where I have the pleasure of joining in the fun.
I'll be looking at the new Sawn Craft Micro F-4D/F-6 Skyray EPS foam kit which uses the electronics from readily available Horizon Hobby micro models in a cool new design introduced in January 2015.
I'd seen this terrific little model here on the RCGroups blogs and I immediately contacted Sawn Craft's Jonathan Sawn. This US-based company in Granby, Connecticut has been producing quality model kits since 1958 and Jonathan was kind enough to forward one of the very first production kits off the CNC miller.
Sawn Craft's micro kits can use the non-AS3X electronics from any E-flite , HobbyZone or ParkZone micro model or an off-the-shelf Spektrum AR6400 "brick" designed for scratch building projects or kits like this one. Propulsion comes from the motor, prop and gearbox normally fitted to the ParkZone Champ or E-flite P-51 Mustang. Since this model will be spending its time outdoors, it will be fitted with the high performance P-51 motor per Sawn Craft's recommendations. Part numbers of the two motors are actually different and since I've flown both the Champ and the P-51, I can say from experience that the P-51 is noticeably faster and higher revving.
So, anyone with a Spektrum, JR or other DSM2/DSMX radio with elevon/delta mixing capability can take electronics which might otherwise be languishing in the junk drawer and convert them to a sweet indoor/outdoor flyer. If one prefers, the F-4D can also be assembled with rudders for use indoors. I like elevons and again, this example is going to be flown outside.
Making this deal even better is Sawn Craft's partnership with the name in model graphics.
Yes, Callie Graphics of Magdalena, New Mexico has teamed up with Sawn Craft for an incredible decal set designed by Jonathan Sawn. These Sawn Craft exclusives will allow the builder to duplicate a number of actual Skyrays complete with two sets of canopy window decals.
Callie Soden had just completed the first set of decals and she sent me some sheets fresh off of her printer.
It's a trifecta of three of model aviation's finest companies in one small, fun package and I'll be reviewing one of the very first kits off of the router to go along with those first decals.
Time to get building after a quick look at the prototype!
The Douglas F-4D, also known as the F4D, F-6 and Skyray was a carrier-launched US Navy and US Marine Corps fighter of the 1950s and 1960s. The "F-4D" designation earned it the nickname "Ford."
First flown on January 23, 1951, the aircraft never saw combat during its short service life between 1956 and 1964. It did, however, hold the world's absolute speed record at 752.943 MPH (1211.7443km/h). 422 units were built between 1950 and 1958. It was also the last aircraft produced by Douglas Aircraft Company prior to its merger with McDonnell Aircraft to become McDonnell Douglas.
The F-4D kit comes with the following:
Electronics needed to complete the model are all available through any Horizon Hobby dealer or from a wrecked E-flite, ParkZone or HobbyZone UMX aircraft without the AS3X feature:
Tools and supplies needed are:
Thanks to the Postal Service, which I generally like, my Skyray arrived in a mangled box. I thought for sure the contents would be just as mangled, but other than a couple of small indentations on the underside of the wing, the kit was fine. Sawn Craft will gladly replace any badly damaged components with an email to firstname.lastname@example.org.
Sawn Craft does a neat job of packaging this kit. It's packaged in a clear plastic envelope topped with a display-quality header card complete with a QR code.
All of the airframe parts are perfectly routed and simply need a bit of dusting off to wipe away some of the foam dust left over from the routing process. Sharing space in the bag are a very nicely written manual and the hardware package. That package has the CF rods, wiring extensions, shrink wrap tubing and such needed to extend the electronic leads, build the pushrods, etc.
Once removed, the contents look like this:
On to building!
Assembly begins with removing the various parts from their sheets. This is a good way to go if one plans on painting and building in a normal manner, but I had to stop for photos between sets. So, I removed what I needed starting with the next two steps, namely laminating the fuselage and wing. The rest of the parts remained on their sheets and were returned to the bag.
Once the parts are removed with a sharp hobby knife, the tabs may be sanded flush with a 220-grit sanding block or sandpaper.
The rear extension tab on the wing which supports the vertical stabilizer and ventral fin had been partially milled off and it didn't take long for it to completely come off. Foam-safe CA was all that was needed to reattach it. No big deal and not a minus.
Easy as can be.
The 6" long, .083" diameter carbon fiber rod is inserted into the recessed slot of the inside of one of the fuselage halves. The halves are then joined with Foam-Tac and allowed to dry.
Once the glue is cured, the leading edges can be rounded off with the sanding block or paper. Doing so gives the fuselage a finished look and helps hide the seam between the halves.
Again, super-duper easy.
With the main wing's milled "brick" location markings facing up, glue is applied to the so-called "KFm step" and applied to the top of the wing. "KFm" is the abbreviation of Kline-Fogelman, the type of wing which is used on this model. A discussion of KFm construction may be found here at RCGroups.
The KFm step acts as a reinforcement for the perimeter of the wing and the forward area where the fuselage is later joined. Naturally, it adds considerable stiffness and no further reinforcement is required.
The manual seems to suggest that the F-4D first be assembled before being decorated. I thought this would be a good time to break out the paints and get to brushing up the airframe parts before installing the electronics and doing the final assembly.
Jonathan was kind enough to share a .gif of the color scheme he used on his prototypes, but since it's based on his CAD drawings of the F-4D, I'm unable to share it here.
The first was painted by a friend at a body shop who used automotive acrylics. The second was painted using Apple Barrel brand acrylic craft paints from Walmart. The selection at my local store wasn't that great, but the nearby Hobby Lobby stocked Anita's All Purpose Acrylic Craft Paint made by The Testor Corporation. These four colors were only 79 cents each. I picked up some Testors hobby brushes while at Hobby Lobby and some foam brushes from the nearby 99-cent store to apply the grey paint over larger areas.
The colors were:
I might also add that Jonathan let me in on a neat secret: He uses ordinary 3M Post-It Notes for masking since they won't lift off the adjoining paint. Some ordinary blue painter's tape also came in handy.
The end result was incredibly attractive and proved easy to see in the air. Better still, the paint soaked into the foam, giving it a sort of velvet matte finish. However, the scheme didn't seem to represent an actual F-4D based on my research. It's a mix of Jonathan's color scheme and Callie's decals applied per Jonathan's CAD drawing and that online research.
Scale modelers may cringe at my ultimate solution, but the F-4D is a blank canvas for those willing to really detail a model of their own based on an actual prototype. Add a set of Callie Graphics decals and the sky is literally the limit.
I'd made up my mind from the get-go to set up the F-4D with the most powerful motor possible and elevons for use outdoors. Sawn Craft actually provides two separate vertical stabilizers, one with a rudder and one without for use with elevons.
The elevon setup is slightly less involved and simply requires that a straight edge ruler and a new hobby knife be used to bevel the elevons where they join with the wing. A sanding block may be used; I used a little of both, starting with a knife and ending with the sanding block. The beveled part goes underneath the model and is held in place on either side by hinge tape. Glue hinges may be used as well.
The hinge tape works beautifully, but required several coats of paint to cover brush marks.
There's nothing quite like the feeling of pulling a brand new control board and motor from their packages only to have to cut the wires in preparation for extending them.
Fair heart never won fair maiden, so out came the wire cutters and the soldering tools.
Once the deed is done, the brick may be glued atop its squared-off area atop the wing with a bit of foam glue. Ditto the gearbox and motor in their clearly marked location once a propeller is screwed onto the gearbox's drive shaft.
The F-4D may look like a pusher prop jet, but it is in reality a "tractor jet" for want of a better term. The propeller numbers are to face forward and the propeller to turn in the usual counterclockwise direction when viewed from the front. The prop and motor felt stiff at first, but they loosened up after the first flight.
The manual states that some down thrust is preferred by some users with the P-51 power setup. This, of course, is to keep the F-4D from climbing under power without effecting the flight characteristics. It suggests using some scrap foam to tilt the front of the gearbox up and therefore the propeller downward, but the alignment dots do a great job of holding the retainer pins of the Champ gearbox. Out came the foam glue and on went the gearbox with the two forward pins just below the surface of the foam. That proved to be a perfect setup.
The battery and motor wires must be routed around the propeller opening per a photo in the manual. Rather than use tape, I used small dabs of the indispensable Foam-Tac to tack the leads as illustrated after installing the two skids and ventral fin. They were first painted to match.
Assembly of the control rods is next. I've done control rods of this sort before, so I began with electronically centering the servos.
The .051" carbon fiber rods and .024" steel control wires are held together with shrink wrap tubing shrunken with a heat gun. The control wires then go into the holes in the servos which, by the way, are a slop-free fit. The opposite ends go into the lite ply control horns and once the alignment is correct, the rods are glued together and the control horns glued in place. I opted for some small dabs of medium foam-safe CA to secure the rods and horns. I should have no trouble breaking the rods loose should I need to replace the brick at some point, but for now, it's a secure and solid setup.
Gluing and sliding the fuselage in place and attaching the Velcro for locating the battery complete the model. The Velcro is applied over a piece of clear tape which is first attached to the fuselage just under the simulated air scoop on the left side. Once the vertical stabilizer is glued in place, the F-4D is ready for decals and, of course, for flying!
I finished the F-4D at night, so I tried some "short range test flights" in the house.
With one of the Lectron Pro batteries in place, the model balanced at the designated 1/4" in front of the propeller opening. An underhanded toss without power across my bedroom to the bed resulted in a smooth glide. A brief burst of power on the second try was even more encouraging.
The test flight the next morning was in ever-so-slightly breezy conditions. Sawn Craft recommends launching the model by grasping a wingtip in one hand, the radio in the other, throttling up full and swinging it into the air. That's the method used in Sawn Craft's indoor video linked below. With the P-51 motor swinging the prop, I discovered on the first try that it would literally fly out of my hand when grasped by the fuselage forward of the motor.
And fly it did.
On low rates, it didn't have quite enough bank to suit my style; I later bumped up the low rates from 75% to 85% aileron before the video shoot. Better, but this little model and my flying style love the high rates.
Like any delta-winged profiler with a large wing area, the Skyray will seemingly glide forever on approach. It wanted to nose down a bit, so I kept the power on for a nearly Harrier-like landing at my feet. Up went the rates, back went the battery a little bit and off went the Skyray for another flight.
Much, much better. Turns were far more aggressive, yet at no time did I feel as if it were twitchy or unpredictable. It definitely liked a combination of throttle, elevator and aileron in turns since it wanted to drop the nose. Before long, I was not only flying beautifully coordinated turns, I was also doing low, fast passes under perfect control.
The model caught the attention of two toddlers and their young mother; the boys were fascinated by what they saw. So too was Mom, for that matter. I showed the boys the model and asked if they'd like to see me fly it once more. They both smiled and nodded their heads; I sent the Skyray skyward once more for a flight I hope they'll never forget. It's reassuring in an age of electronic marvels that a model aircraft can still instill such wonder.
A later test on a dead calm Saturday afternoon at another local park before the video shoot was even more encouraging. Sawn Craft claims that the F-4D flies "bigger than it is" and they're correct. With no wind, the F-4D goes exactly where it's pointed with surprisingly good speed and no drama. While it will happily perform loops, it won't roll. At least I couldn't get it to roll. No matter; it was simply fun to fly, especially those low, fast passes over the grass once more.
As with the maiden flights, the Skyray became the immediate focus of a group of children at a nearby birthday party. Within moments, I had an enthusiastic audience of both kids and parents asking questions. One utterly fascinated little fellow kept asking if he could try flying it. Standard question from a child, but since flying the model looked so effortless, who could blame him?
I scored another dead calm morning for the video shoot at the Coachella Valley Radio Control Club, the site of virtually all of my flight tests and videos. As always, club videographer and historian George Muir was on hand to record the action out at the combination U-control, park flyer and helicopter pad. On our way to the pad, the F-4D caught the eye of club president Dan Metz.
"Is that an F-4D? A Ford? Cool!" Dan knows his aircraft to be sure.
After launch, the little model showed once more that size doesn't necessarily matter when it comes to great flying characteristics. The Kline-Fogelman wing design does its job to near perfection, allowing the Skyray to swoop in circles, figure eights, loops and low passes for the video. So calm and in such control was the model that I was able to land it practically at George's feet for the finale.
My only concern was that an asphalt landing would scrape paint from the skids or nose, but I needn't have worried. All it had was a tiny streak of black beneath the orange nose which I later touched up with paint.
While the F-4D will loop with plenty of power from the P-51 motor - I can't vouch for the Champ motor - it won't roll, even at 100% throws. It looks as if those little linear servos can be over-driven somewhat, but I don't wish to chance it. I've used the Spektrum AR6400 brick in other micro models and they seem to have a bit more throw. I might be wrong, but since it's the same price as the Champ brick, it's worth trying if one is starting with all new electronics.
What really makes this model a standout is the surprisingly brisk speed, the rock solid flight characteristics and the sharp, accurate control.
I would say yes to an extent. Someone comfortable with a UMX warbird or aerobatic plane will have no problem whatsoever flying the F-4D. If one's only experience is with a Champ, it should be noted that an elevon equipped, delta winged fighter jet handles quite differently than a three-channel, high winged model.
This is one fun little flyer. Here am I on the U-control/helicopter/park flyer pad at the club field:
|Sawn Craft Micro F 4D Skyray Kit - RCGroups.com (2 min 3 sec)|
Sawn Craft did an indoor video of their own:
|Sawn Craft Micro F-4D Skyray - Flight Video (3 min 24 sec)|
At a mere $25, the Sawn Craft Micro F-4D/F-6 Skyray is an insanely fun, affordable way to breathe new life into old electronics. Those same electronics are proving to be the small-block Chevy of the micro aircraft world with their versatility. Add to that the quality and top-notch support from Horizon Hobby.
If one is starting with existing electronics, the Skyray can be assembled for less money than it may cost to replace or a factory fuselage. The result would be a truly a one-of-a-kind micro flyer. I started with new electronics which set me back about $115 including the batteries. Add to that the cost of the paints and other supplies and the F-4D is deep in receiver-ready micro territory. However, it will be a micro of exceptionally high quality, one which can be detailed as the builder prefers and can be easily repaired if need be.
Two thumbs way, way up. This is a model which is going to see a lot of use at the local parks.
Thanks galore go to Jonathan Sawn of Sawn Craft for providing this marvelous little kit. Sawn Craft has been producing quality models since 1958 and their experience shows in this great design. I am always grateful for the terrific products I get from Callie Soden of Callie Graphics. Her work is simply beyond compare. I can always count on George Muir of the Coachella Valley Radio Control club for his excellent videography; he's always as close as a phone call or email.
No review at RCGroups.com is possible without administrators Angela Haglund and Jim T. Graham who work behind the scenes posting these reviews for you, our terrific audience all over the world.
Thanks once more for visiting RCGroups.com!
I have a rare neutral comment:
No minuses were noted.Last edited by DismayingObservation; Mar 16, 2015 at 08:12 PM..
United States, TX, Benbrook
Joined Nov 2012
It's Not an F-4D
Nice review...but...please don't call the Skyray an F-4D. That's the designation of a version of the Phantom used by the USAF. The Skyray was originally designated F4D-1 before SecDef McNamara got all confused. It became known as the F-6A after McNamara's problem. Judging by the many messed up designations seen these days in ads and text (such as F-4U, F-9-F, B17, etc.), there is still plenty of confusion regarding correct designations.
Thanks, gentlemen. More good stuff on the way from a lot of different manufacturers. I'm hoping to get another Sawn Craft model at some point down the road; this is a very well designed little model. As for the designation, I went with what Sawn Craft called the model, but thanks for clarifying the issue. My opening paragraph which told of the prototype was taken almost verbatim from Wikipedia which listed three different designations for the same aircraft.
Quite right on calling it by the right designation to help people to understand what plane it is and not get it mixed up with another type of aircraft. Understandably the confusion of making it correct.
I got two of these kits which I built one for seeing how it flies, it's a wonderful flyer and a very simple design, the kit is well done, construction is straight forward and quick ( I took about 2hr from start to finish) I flew it at the National building museum here in DC . The flying area is small and as you can see from the video I am flying it with ease. I will start soon on the second kit and will detail it.
Nice job on the review Ralph. I think this kit is going to be popular.
Thanks, New! I love the surrealistic look of the video with an all-white plane buzzing around the inside of a museum.
Baj, I didn't get any screen captures from George this time around. I'll remind him the next time we get together. Or, I'll do it myself with the new computer. Fact is, I didn't even think of it.
Ralph, there has never been a better time than now to get into digital photography! As you probably know, just grabbing screen shots off of video will result in low quality photos. Getting and using a DSLR or mirrorless digital camera with a reach of 200-300mm will allow you to showcase the products that you review in their native element.... The skies! I really like some of the Sony mirrorless cameras. Another dollar saving suggestion is to peruse the used gear on BHPhotoVideos web site. I have bought quite a few used products there and they are always very good quality. Your reviews are quite detailed and enjoyable to read IMO. But they make me resort to the imagination when it comes to getting to see the product doing it's thing!
Beat ya to it.
I'm using a Canon EOS Rebel T3i for the build and beauty shots and have been for a little more than a year. Haven't fired up the old point-and-shoot in ages.
I'll pop the telephoto in place ask George to snap some action pix with that camera for the next review. I like using stills of a model in action. Thanks for the suggestion.
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