INSANE NEW GIANT RC GLIDERS - EXPLORER Q4 - HIGH PERFORMANCE TOP LEVEL - NAN-Models - F5J (12 min 2 sec)

Here is a great Video from our friend Julian on the new Q4...
Excellent as usual, from a great pilot, and great guy!

Enjoy!

Bro

Can’t wait!
Looks gooood.

Nice sailplane. When do they make a USA appearance?

I have been flying 4m Q intensively for 3 weeks. Delivery of my model was delayed for almost a month due to packet getting stuck in terminal in Frankfurt because of covid-19. However assembly was really easy and quick, taking less than evenings of a week. Actually my first remark with Q is that NAN has put plenty of work into making the model as user friendly as possible. Especially the modular fuselage is very clever and practical. Best in the industry I would say.

The version I have is 4m v-tail. I have also flown it with x-tail boom and tail feathers taken from my old F3J Xplorer 3. The conversion from v- to x is very easy, requiring no tools. A 5 minute job. Just plug new tail servos to rx and tape the boom to fuselage center pod. As the x-tail elevator and rudder are slightly heavy they automatically move cg slightly aft for x-tail, requiring no adjustments to nose cone.

With v-tail my Q weights 1235g. X-tail is 10-15g more. It is surprisingly light weight for a 4m model - and I even did not try to make it very light. I have large flap servos, robust wiring, 650 4s battery and Schambeck 1020 motor. Model is not at all weak in air. I have many times flown it in rough air and fairly strong wind with ballast, and it did not feel at all uncomfortable. The downside of low weight is that wing carbon skin is quite thin compared what we have previously seen in Explorers. Take care on the ground and in transport.

The real point of Q is that wing aerodynamics have been changed in the area near tips. The result is not easy to describe. Q feels faster than BF but the familiar Explorer feeling is there. I am frequently surprised how light I fly the plane. Due to lighter weight control response is also imporved, less inertia in tips.

Actually I fly my 4m Q pretty much same same weight - or even slightly lighter - that I would fly 3.8m BF. Weighting 1235g 4m Q is very close qualifying as an FAI-limit ultralight, but it is not restricted to light winds! 100-400g ballast makes it very practical in medium winds. Not bad at all. Largest ballast I have flown is 400g and the tubes have capacity to at least 800g. You will never run out of ballasting options with Q

Regarding v vs. x tail, I do not really know which is better. You probably have your own favorite. 99,5% times I fly the same flights with both tail types. I have flown Explorer v-tails for a few years but recently I have been slightly inclined towards x-tail because trimming is more straightforward, cg it is less critical and I also think that rudder response is a little more predictable. Plane with x-tail has also different 'sit' in air compared to a plane with x-tail, but this not make one better than the other.

I have also entered one competition with Q. Frankly, during preliminaries having a new plane did not improve my flying (it never does). Despite having finished Q more than a week before, there was some trimming issues in the varying conditions in competition. I also made mistakes in ballasting - a couple of times I flew the plane too heavy. I also had too much snap flap and thermal camber. However, thanks to minor adjustments between the 12 preliminary rounds Q got better and better. In 8 pilot fly off I managed to 3rd position and securing silver medal in 2020 national ranking. Nice result since our F5J scene is quite competitive and there are at least half a dozen pilots who can win a competition, given a good day.

Q is definitely a step up in performance compared to previous Explorer versions - a kind of sport version of all Explorers. We are talking about somewhat similar improvement as BF was compared to the Explorer classic. In future 4m Q will be my #1 F5J competition tool. Also, if you are interested in GPS light, Q is your weapon! The glide in medium to high airspeeds is so much improved that sometimes it is hard to believe. And if you skillfully trade this better flight in high air speeds into flying the plane lighter, you also get better thermal climb and improved floating performance.

Just get out and fly

Nice plane! Just curious, assuming that's a Jeti RX. Why do you put the full length of antenna whiskers out like that? My understanding is the actual antenna is the last 4-5cm (the yellow part).

Originally Posted by ptxman

Nice plane! Just curious, assuming that's a Jeti RX. Why do you put the full length of antenna whiskers out like that? My understanding is the actual antenna is the last 4-5cm (the yellow part).

In this plane I have Jeti rx with 20cm antennas. I know 20cm is a little long for this installation, but I wanted to get flying quickly. Shortening the antennas is not difficult but it takes some time and makes me a little nervous

Actually, from the point of view antenna placement, this installation is not much different from slim fuse BF installation where rx is in wing. Almost everybody has had long antennas simply hanging out through servo cover and a hole in the upper side of wing. That works perfectly.

Julians latest video

SMOOTH AEROBATICS with HUGE RC-GLIDER - INSANE EXPLORER Q4 F5J - NAN-Models (4 min 47 sec)

Long non active antenna is not a bad idea as the problem in carbon airframes is shadowing rather than radio interference.

There is no such thing as "active antenna" in our domain. Just take care that at least length equal to monopole (unshielded) part protrudes from airframe, 60 mm in practice. Shadowing is more or less theoretical phenomena, as surface-wave propagation over carbon exists.

Aaro

Originally Posted by JuanMartin

Long non active antenna is not a bad idea as the problem in carbon airframes is shadowing rather than radio interference.

Tuomo, thanks for the nice report. I assume you are a NAN team pilot From your pics it looks like the center panel is same as the BF center panel. Curious what servos you used . As soon as the plane's exact span and areas are published I would like to include your Q in the comparative spreadsheet posted here. Thanks!
--Chris

Originally Posted by Tuomo

In this plane I have Jeti rx with 20cm antennas. I know 20cm is a little long for this installation, but I wanted to get flying quickly. Shortening the antennas is not difficult but it takes some time and makes me a little nervous

Just to be clear, I'm not talking about physically shortening them. Just pulling the excess inside the fuse so that basically only the actual antenna portion (yellow) extends. I got lower reception values when mine were long like that. I think what was happening is they were simply blowing back and/or under a surface blanking area. Mine are positioned either side of the fuse at a slight angle backward so pretty much 'in sight' any normal model orientation relative to TX. The range reception values improved to the extent I will lose the model visually before RF range is an issue. I didn't want to go on an antenna tangent on your Explorer post, but mentioning just in case.

Originally Posted by gerhardl

Julians latest video

https://youtu.be/BAkICXbHEYY

No need to worry about range when you fly like that!

Originally Posted by G.P.

No need to worry about range when you fly like that!

Man, it's amazing to watch the talent some of these youngsters have! I could be flying 24 hours per day for ten years and I would still not be able to do one tenth of these precision moves!
Kudos to all the young people taking the sport forward

Originally Posted by ditman

Man, it's amazing to watch the talent some of these youngsters have! I could be flying 24 hours per day for ten years and I would still not be able to do one tenth of these precision moves!
Kudos to all the young people taking the sport forward

Same here, too old to keep up with them!
Methinks you start with a 3d Foamy, not a $2500 f5j!

But we are talking about actual shortening - Tuomo being nervous about it means only that I will shorten them for him Shortening the whiskers makes them stay easier perpendicular to fuse instead of bending along the airflow thus bringing them too close the carbon. Some shrink tube will also be added to keep them stiff. From antenna theory and practice point of view, optimal length of protruding monopole antenna above a conducting surface is twice the length of the radiating part, ~60 mm. No more, no less.

Back to topic. I maidened my 3.5m X-tail Q today. TOW is currently 1115 g with some not-final equipment, weight will go yet a little bit down. Lamination is "light", the one between "std" and "FAI-light". Q is as agile as earlier BF but flies faster and lighter. Aileron response is different from normal BF, probably due to trileron. Anyway, just different adjustments, same precise response exists though. The only own structural add-on was to add ~45g/m2 carbon patches to wing servo cavities before installing the servo frames - the wing lamination, as light, might suffer if for some reason there would be need to detach the servo frame.

I use new KST HS08-servos and IDS in wing, including flaps. With 6 volts there is completely enough power, one does not need to be shy when deploying the flaps. Time will tell how slop generates as the gears are quite tiny. Fuse servos (in tailboom) are KST X08. Motor is this one, prop is GM 12x8 and battery will be (not yet arrived) a 4S 450mAh. Low amps, enough power. Today I flew with 3S 650 mAh, hovers and goes vertically up but could - and will be - faster with tiny 4S.

SoaringDude; the areas and dimensions are identical to previous versions, no differences there. Attached are dimensions of the versions discussed here.

Aaro

Originally Posted by ptxman

Just to be clear, I'm not talking about physically shortening them. Just pulling the excess inside the fuse so that basically only the actual antenna portion (yellow) extends. I got lower reception values when mine were long like that. I think what was happening is they were simply blowing back and/or under a surface blanking area. Mine are positioned either side of the fuse at a slight angle backward so pretty much 'in sight' any normal model orientation relative to TX. The range reception values improved to the extent I will lose the model visually before RF range is an issue. I didn't want to go on an antenna tangent on your Explorer post, but mentioning just in case.