...sporty stripes This morning I hauled out the Stinger for its second flight without wing decals, and its first with a new striping pattern on the wings, the graphics consisting of two simple stripes using electrical tape. The morning was, unfortunately, rather grey, so visibility wasn't all that clear to start off with, so it was perhaps unsurprising that the stripes didn't show up to any significant degree as the Stinger howled over the paddocks.
This was a minor disappointment, however, although the cleaner wings are still a substantial improvement over the original. I have subsequently added to the striping, with an adjacent black stripe, and have give the Stinger another run. This setup looks pretty good, with better visibility, although I still find I need to be much more careful with the Stinger...
...good and bad This morning I plucked up the courage to get the Raptor Glider out for its first flight at the paddocks. The morning was eminently suitable if not spectacular; cool and overcast with a gentle northerly blowing across the field. The Raptor was flying with a 2200 25C 3S battery and 11x6 carbon props, powered by a spare Phoenix motor I had on the spares shelf, a setup-up which should provide sufficient urge to motor the Raptor along. Not that one needs an over-powerful setup for this type of glider; with broad two-metre long wings anything exceeding a pedestrian pace will have the lightweight Raptor heading straight up with the amount of lift it generates.
The Raptor, while significantly different in construction to the Phoenix 2000, is not dissimilar in overall proportion and design, so it was fair to expect similar performance. The main difference was the V-tail which, although having flight characteristics no different to a conventional layout, is a little concerning nonetheless. Although the CoG was spot-on, I moved the battery to the front of the tray just to be sure, based on my experiences with the big Phoenix. So, having checked the control surfaces and reassured myself once more that the V-tail controls were really moving the right way, I powered up the motor ready to go. The Raptor was instantly tugging at my hand, straining to be let free, so with a touch more power and a good throw, the big glider slid into the air. My immediate reaction was how gently it flew and, after a few seconds, that one needed to be careful on the power as it was nosing straight up, just like the Phoenix 2000. Dropping the power and levelling it off had the Raptor cruising slowly over the paddocks, my unease over the V-tail having dissipated with it behaving quite normally in all respects, except that I needed to adjust again to the slow roll rate of such big wings. Things were going along peacefully until an ominous rattle was heard from the prop, so I cut power and glided down the raptor. Although I didn't manage to get much flying in, this brief opportunity to glide it showed just how well it flies, appearing to have an excellent glide angle and very stable manners. A quick check under the hood once the Raptor was down revealed, rather startlingly, that the motor had come loose despite the mounting bolts still being well secure. It appears that the motor came loose from the bell mounting, perhaps the fault of a loose grub screw, despite it being brand new...
...sleek, fast and bitey Yesterday was the last of the forecast hot days, but dawned a beautiful morning with a steady northerly breeze, not yet carrying the heat from the interior. I'd packed the Fox with the carbon prop installed again, now with reinforced motor mount to hopefully eliminate the full-throttle vibrations it had been suffering. I threw the sleek little glider into the air, enjoying it's swift and graceful flight against the backdrop of fresh morning clouds.
The carbon prop and nanotech battery have, as I've mentioned before, gives the Fox unlimited vertical capability, and I was enjoying powering the Fox up and then gliding it down, and having it swoop low across the field before repeating the exercise. Now I know, and have also mentioned, that the Fox is a high-speed glider and possessing a nasty propensity to spin at low speed but, lulled into a failing sense of security, I pushed the limits too far, with the Fox too low and too slow. The spin was sudden, violent and beyond my capability to recover...
...sleek, slim and a tight squeeze The Raptor Glider is now completed; set up, tested and ready to roll. While it goes together pretty well, there are a few items worth noting. There are two pairs of servo housings provided for aileron and flap; as well as covering the servos they also double as servo mounts, with the servo screwing directly onto them. However, being supplied in pairs, this causes a problem for the flaps as the operation becomes mirrored; necessary for ailerons but not for flaps. My solution was to install a servo-reverser, substituted for one of the flap servo extension cables.
On the subject of extension cables, the rear of the fuselage, where the extension cables plug into the Y-cables, is very small area due to the sharply tapering fuselage. In order to accommodate the plethora of wiring, I had to feed all excess length of the servo extensions back into the wing cavity. Even then there was just sufficient room to fit the bulky Y-cables and connectors.
The lack of room here is also a casualty of the general layout; while the ESC generally fits neatly under the battery tray, due to the Raptor's battery tray being so low-slung, there's barely enough room for the cables to run underneath. As a result, the ESC sits aft of the battery tray, where I'd usually site the receiver and, because I want the receiver away from the battery and ESC, this got relocated in the back of the fuselage, where the cables would usually be sitting...
With a 2200mAh 3S lipo up front, the weight distribution is virtually spot on, with space to move the battery a little forward to make it slightly nose-heavy if you need. So, everything's fitted and functional, just waiting for a trip to the field...
...the single-wire solution The Raptor glider comes with a smooth-fitting carbon shell of a canopy but unfortunately, despite R2hobbies' product description, this doesn't come with a canopy latch mechanism. After some deliberation, including two type of spring-loaded canopy latch mechanisms, I decided to go with the single-wire system. For those not familiar, this basically entails gluing a strip of spring wire to the underside of the canopy, with the ends extending past the canopy shell front and back.
The idea is that the front wire is slid under the fuselage rim at the front of the canopy recess, and then the canopy is pushed far forward until the back wire can be slipped under the fuselage rim at the back. The canopy is then slid back into it's recess.
For the wire, I used a length of excess control rod cut from the fuselage push-rods, and hot-melt glued this to the canopy. The extent of gluing affects the amount of retention force - closer to the extremities means shorter wire flex and therefore greater retention force, although this also places more stress on the canopy so this is a balancing act. The length of wire also needs to be adjusted as excessive length can cause fouling at the front or problems tucking in the back.
I'm a little uncomfortable at having to deform the canopy each time it's fitted and removed, but it doesn't appear to stress it unduly. The appeal of this system is that no modification is required to the rather delicate canopy as would be required with canopy latches, and that the result is an unblemished external appearance; the canopy held in place as if by magic...
...going to plan so far I had hoped to have the raptor ready for a first-flight today, although that turned out to be overly optimistic.It also turned out very mist at the field, so I wouldn't have flown the Raptor anyway with visibility that poor. So far I have installed the fuselage linkages and servos, and hooked up the tail surfaces. I have also managed to complete the installation of servos and covers on one wing, including the slightly tricky task of feeding the servo cables through the wing spars. Fortunately, with the generous sized cutouts and and improvised threading tool (control wire with a hooked end) this proved less troublesome than I had anticipated.
One thing worthy of note is that extension cables need to be firmly plugged in, given that the cable has to be pulled past obstructions. After one let go during the process, I taped up the connection with electrical tape to make sure it stayed fast. So I hope to have the other wing fitted out soon, then I should be able to connect everything up for a functional check. I've set up the V-tail mixing on my radio, (right=rudder, left=elevator) although I still need to check whether either of the controls needs reversing, and to make sure the tail does what it's supposed to...
...better but bigger With the Raptor glider being ARF, I'd spent some time reading posts regarding what kit people had used to complete the build. As far as servos were concerned, most people used higher-spec ball-bearing servos and, just to be sure, I decided to follow suit. The servos arrived, each separately boxed as well as being bagged inside; over-packaged if ever I saw it. However more annoyance was in store as I discovered that the bearinged servos, in order to accommodate the extra gear, had the casings extended downwards, with the result that the swish new servos were too deep for the laser-cut mounts, with the Raptor having the servos installed on their sides. The cut-outs are in fact the exact size of the Turnigy TG9Z servo but, due to these being apparently sensitive to binding & alignment, I was only going to use for the flaps. So, after renewed reviewing of servo specifications & sizes, I decided on the best servo for the job; smaller, stronger, cheaper and very familiar. The faithful HXT900...
...too much of a good thing I recently received a box of goodies containing items to finalise the Fox glider; a 32mm carbon spinner, a pair of carbon 9.5x5 folding props and a new battery. The reason for changing from the standard setup was that the R2hobbies spinner has an inboard pivot which prevents the prop from folding, and additionally I thought the standard 10x6 props too large.
On the weekend I had a chance to get the Fox out for a trial run with its new hardware, and got something of a surprise; the setup, powered by a 25-5-C 1800 Nanotech, developed that much thrust that it put the Fox into a turn at full throttle, and caused a vibration past about 80% throttle. Consequently I've decided to try out a set of Walrus props I've got in the spares drawer. These are about 8x5 and I think should be a little more suitable. Anyhow, I've got the Fox set up and will give it another test flight soon...
...what gets your spirit soaring People's reaction to the planes varies a lot; some people are mildly interested, some could be mildly annoyed at the disturbance of the peace, whilst others are obviously captivated by the magic of flight. You can never really be sure, so I tend to keep the planes quiet and flying away so as not to cause disruption.
This morning I met a couple who arrived with their dog for some early-morning exercise at the field; talking to them as I headed back to the car with Canadair in hand, they'd been captivated by the sight of the water bomber flying around the morning sky. And, the other day, I spoke to an ex-pilot out walking his dog, who'd enjoyed the speed and grace of the little Fox glider as it enjoyed an evening flight against a dramatic backdrop of clouds...
...exquisite tranquility Yesterday evening was a rarity; the gusty weather of the afternoon abated whilst there was sufficient light to fly. Additionally, and most compellingly, the greasy cloud cover of the day have developed into a beautiful array of shapes colours and textures, enough to have me grabbing the Fox glider and heading for the door; delicate balances like this don't last forever.
Despite remnant players from the afternoon cricket match and a boisterous Retriever pup being walked on the field, I decided to get the Fox up so, with a bare minimum of preparation (no pre-flight video!) I had the Fox purring sweetly into the lovely evening sky. Flying was an absolute joy, scenic and incredibly tranquil; the only detraction was having to cut the flight a little short as, with the field mostly ringed by trees, having enough power on tap to clear them is imperative. Nevertheless, darkness was encroaching by the time the Fox bumped over the cricket pitch for a landing, and I headed for home with the lingering delight of having experienced something special...
...hopefully better visibility The biggest issue I have with the Stinger, apart from the super-sensitive aileron setup I had on the first flights, is visibility; the Freewing version has classic sport-jet stripes on the white wing whilst Hobbyking, for their Mk2 version, unfortunately decided on a bespoke black-and-lumo full-body decal. While including a scorpion graphic was kinda groovy, the overall effect is a 21st century take on camouflage. Unsurprisingly, although you could easily see the Stinger in the air, I've found picking the orientation, particularly wing angle change, to be very difficult. Even the tiny Rarebear is much easier to see. And, given that the Stinger is always a little touchy to fly, in combination with the camo decals, it's virtually heart-stopping.
Consequently I've embarked on a degraphic exercise; first of all I removed the decals off the tail-fin, working on the premise that this is the most visible feature on the Radjet. Unfortunately with the Stinger this was unsuccessful, so I've just finished clearing the second wing, making it look rather naked. While this may not be optimum, I haven't the enthusiasm to stripe it and I'll try it out first to see how it goes; and judging by how easy it is to see change on angle on the Rarebear tiny white wings, I think it will be a big improvement. Then, at some stage in the future, if I come across a suitable set of stripes, I'll pimp up the Stinger so that it looks a little less bland...
...an interesting turn of events From the first few flights it was apparent that, in my opinion, the little Fox was over-propped, especially running just an 1800mAh battery. Also, the R2Hobbies spinner setup is very dodgy - the inset pivots mean the props cannot fold flat as they foul the fuselage by a mile, and the prop mounts only fit a 6mm base, meaning the props have to be filed thinner to fit, weakening them considerably. I discovered this first-hand when, landing the Fox with the prop still windmilling because of the unbraked ESC, a sudden snap indicated that one of the prop blades had given up. Consequently I've ordered a new 32mm carbon spinner and a 9.5x9 carbon folding prop to match, slightly smaller than the original prop to spin a little more freely. I've also ordered a 25-50C 1800 nanotech battery to give the Fox a little more grunt than the pedestrian pack it's running on at the moment. However the biggest surprise came from the spare parts shelf. Hunting around for a replacement prop, I came across some Walrus props, about 8.5 size, which I thought might do in the meantime, and filed these down to suit the Fox's mini-mounts. As well as being a bit smaller, the Walrus props are also cranked forwards which help the props to clear the body and fold better. Not expecting too much, in fact virtually expecting the rework white plastic blades to disintegrate at the first hint of full throttle, I was amazed at how sweetly they worked, with the Fox humming happily through the cool morning air...
