IAD

I may try a turbulator, if my latest set of fixes doesn't work. (If that's what you're talking about, JadeFalcon. Was your addition oriented spanwise, or chord-wise?) Putting it plainly though, I don't think that at this size/weight/speed, the inverse spanwise flow is playing a significant role. Don't forget, this aircraft is capable of maybe 35-40 MPH, max., and has a wingloading of less than 9 oz/ft^2.. It's hard to describe, but what I've observed is that at wingloadings below about 10 oz/ft^2, the shape of the wings is increasingly less significant. (As long as the area is there, you're good to go.) For example, I've flown an aircraft with rather forward-swept wings (see attached) without any problems. If spanwise flow was a serious issue, there should have been a massive nose-up pitching behavior, which simply never happened. Again, it was very light, and flew relatively slowly, at 25-30 MPH, max.. (Interestingly enough, since the swept-forward wing setup worked so well, I think a YF-19 just might work.) Now, from what I've observed, a heavier, faster model (like your low-wing ship) is much more sensitive to strange wing planforms, and things like turbulators, stall-strips, and wing-fences do their respective jobs better. I don't think this will ever be a real hotrod, so for me, the object is to get the best low-speed control possible. Of course, this means sensitive controls at higher speed, but again, these lightweight aircraft are pretty easy to fly. Aside from nosing down in flight, it's actually a very stable airframe. HWR, I actually don't have any subscriptions to model magazines, so they were sort of the last thing on my mind. Keen idea, though. Originally, I planned not to have any aerodynamic controls, but decided some small ones just to help with keeping things under control in the event of a motor-out condition would be a smart idea. If you look at the photos though, you'll see how small the control-surfaces are. Considering their close proximity to the center of gravity, they can never be very effective. The canards will help with pitch quite a bit, as they are quite far forwards of the center of gravity. In terms of roll, my best guess would be that they won't have much effect, since they are still rather small, and don't have much leverage to get all that wing and what-not moving. Anyhow, I hope to slip a flight in tomorrow (Friday) but there is a lot of rain predicted from a distantly-passing tropical storm... If I can just get 20 minutes of good weather though, I'll go for it. ~Luke

http://www.rcgroups.com/forums/showpost.ph...3&postcount=206 The latest modifications, rectifying identified problems. Behold the deflection capability on the canard! [Evil laugh] (HWR, I'll get you those pictures of the thrust-vector system tomorrow.) ~Luke

Yes, I would definitely make the underwing stores removable, just in case they foul the wings too much. Seems the outermost pods are almost mandatory for the SV, though. I've seen video clips from other RC flyers in the UK... Your fields are so nice........ All we have around here (CT, USA) is a bunch of weedy fields... Or fields where people don't want you flying. The weeds are good for crash landing in, though. ~Luke

Still crashing along, though this morning I made some major progress in figuring out the peculiar aerodynamics of the airframe. I logged another extremely short flight on Saturday, with the same loss of pitch response as the airspeed increased. As far as I can tell, this problem arises due to the unfortunate combination of the use of flat-bottomed airfoils on the stabilizers, the abnormally large size of said surfaces, and the unusual angles at which they are mounted. These three things combine to create a nose-down pitching force, as the speed of the aircraft increases. The final nail in the coffin is the fact that as the nose pitches down, the aircraft gains even more speed, thus causing further pitching, etc... On the bright side, there are several possible means to fix this problem, all of which are quite straightforward to implement. I hope to have enough time to get the modifications fielded by Friday. ~Luke

Will do, as soon as I get another flight in. (Tried this morning, but things went south, as they say.) ~Luke

It uses a pair of these: http://www.balsapr.com/catalog/motors/Feig...oductId=U025875 Mounted in a pair of these: http://www.balsapr.com/catalog/motors/duct...oductId=T786626 I went and found some Macross Zero music videos, which seemed to encompass pretty much every major aircraft engagment in the movie... I read up on the storyline, and since I hate the new-ageist spin the later episodes took, I'm none too keen to actually watch the whole thing. The fights were great, though! :cool: The VF-0 could be a serious pain in the neck... Aerodynamically, it's rather inferior to the SV or YF-22... Probably even worse than the YF-19, which is saying something. I do wish somebody would build one, though, so I could out-fly it with my SV, thereby demonstrating the inherent superiority of the Russian/Israeli design. Speaking of which, I managed to slightly damage the airframe again... The new center of gravity was too far back, which resulted in a bit of a disaster. It's been fixed though, and is awaiting another test, tomorrow morning. ~Luke

Interestingly enough, the YF-19 (fighter-mode, obviously) is another design that I think I could get to fly... Not promising anything here, but there may be one built in the not-so-distant future... ~Luke

You know, everybody's been asking me that. This is what I told them: If you're willing to buy the trio of $200 motors, $100 fans, $500 (yes, five-hundred-dollar) battery pack, couple dozen servo-motors, stabilizing gyroscopes, etc.... I'll build it..! ~Luke

Well, everything's repaired/upgraded. The new battery location should solve the CG issue. ~Luke

Well, already I've got the wings back on. I should log another (hopefully 10-minute) flight on Friday. ~Luke

Ok, you can read all the details on the first flight right here: http://www.rcgroups.com/forums/showthread....=10#post4264256 Be warned, there was a bit of carnage, but I'll be back in the air within a week or so. Just need to work out some balance issues. ~Luke

Took some photos. Still need to slap some insignia on the thing, and move the squadron-marking back a bit. (It's just a paper cutout, tack-glued in place.) By no means perfect, but still perfectly acceptable, in my opinion. ~Luke

Well, I've just about finished it. A few odds and ends to tie up, but I've got the electronics driving the control system in, and everything works. I'm over my objective weight, but still hoping for the best. (13.25 oz., ready to fly.) If the weather holds, I'll be taking my shot at flying it over the weekend, sometime. ~Luke

Well, late as usual. But, take a look at the paint-job! (WIP, I might add.) http://www.rcgroups.com/forums/attachment....chmentid=579230 Now, I know it isn't perfect 'scale' and Ivanov would probably be turning over in his grave (if he hadn't been vaporized...) But, considering I don't have an airbrush, and have to keep the weight under control, I think it's close enough. ~Luke

Almost, almost. I've got one fan mounted, the speed controls mounted... The bottom of the nacelles are finally finished... Oh, and I started playing around with some paint. (Just a little, I'm not too sure how much weight I'll have to play around with, after everything's installed.) Almost. Oh the suspense of it all! ~Luke P.S. I need to pick up some better gold paint, I know. Stupid cheap stuff I had laying around.

Dunno, really... I mean, if I were to really push, I could probably finish within the week... I'm shooting to have it up and running by the end of the month, though. Better to do it a bit slower, and do it right, than to rush, and pile the whole thing into the ground because of something dumb... ~Luke

Not a huge amount of new stuff added, but it's getting there. http://www.rcgroups.com/forums/showpost.ph...36&postcount=70 ~Luke

On the contrary, I'm worried that I'll end up tail heavy. The ducted fan units each weigh in at an ounce, so that's two ounces quite close to the extreme rear of the aircraft, plus another 0.5 oz or so, for the speed controls. Furthermore, the CG is surprisingly far forwards, somewhere around the leading edge of the root of the wing. The servos and reciever only weigh about 0.6 oz., and these are mounted up in the nose. The battery (3 oz.) will be mounted somewhere inside the stub wing/LEX, just ahead of the CG. Fortunately, I have quite a bit of room in there, so I can move the battery around, until I get it to balance correctly. ~Luke

Thanks for the compliments! Some new pictures are posted on RCG: http://www.rcgroups.com/forums/showpost.ph...49&postcount=53 I'll admit, I'm a bit behind schedule here... But, at least progress is being made. The control system was quite hard to set up, but now that it's pretty much done, things should start moving a bit faster again. ~Luke

Yes, a slightly larger version would have enough weight-carrying ability to support a micro-servo for each vane. ~Luke

Thanks! I've just posted a short video clip, showing a trio of the thrust-vector vanes working. http://home.comcast.net/~nsknews/ThrustVector.avi (Right-click and Save As. DiVX compression.) ~Luke

To give you an idea of where I stand right now... ~Luke

Well, let's see... I've got to finish the control system, (letting the paint dry on the vector vanes as we speak) install the ductwork, and finish the bottom of the nacelles, and the lower vertical stabilizers. All of this should be done late tonight, maybe tomorrow, if I get side-tracked. After that, I will spend a bit of time painting the whole thing (carefully minding the weight, all the while) and then order the ducted fans and motors. After that, maybe a day's work or so, to install the fans, and wire them up. So, I'm getting there. ~Luke

Finished the thrust-vector paddles, and a few other odds and ends. The top paddles are hinged, haven't gotten around to the bottom ones yet. 4.25 oz.. ~Luke

Thanks! Just wondering. Some more pictures posted on the RCG thread... I'll throw one in here though... Got the top of the nacelles done. So far, the whole thing only weighs 3.75 oz..! (The maximum acceptable weight for the empty airframe is 6 oz.) ~Luke