Very disappointed by the results !
The Castle Creation Thunderbird 9A controller is not powerful enough to stop the prop from spinning, even with "brake" on. So the sink rate is very bad.
At AUW of 286g, climb rate is +3m/s, which was expected, but sink rate is -1.4 m/s with or without flaps. This is identical to 335g !

I had bought the Merlin Tuning kit, but this setup has a problem: the ESC (BL-20) is oversized: 20A, 27g, 2A BEC. I replaced it with a Castle Creation Thunderbird 9A: just 17g, with 1.5A BEC. I also bought a very light battery: 240mAh 25C.

With this new setup, the AUW of the Merlin was brought down. Without battery: Main part 181g, wings 2x38g, stabs 12g. Total 269g.

Lightest setup, with 240 mAh 2S battery: 286g (-30g, -10%).

Here are some power measurements taken with the 8x5 prop from the tuning kit.

2S / 240 mAh Hyperion G3 CX (25C/5C) / 4.3A 30W (17g)
2S / 460 mAh Rhino 25C / 4.5A 35W (30g)
2S / 450 mAh Extreme / 4.1A 28W (28g) (old battery)

3S / 450 mAh Hyperion G3 CX (25C/5C) / 7.7A 85W (43g)
3S / 400 mAh 30C/5C EX DUALSKY / 7.7A 85W (44g)
3S / 450 mAh EMax / 5.5A 50W (50g) (old battery)

30W for the Merlin gives +3m/s of climb rate, plenty !

Just one word about the Castle Creation Thunderbird 9A controller: it makes a "bip" every 20 seconds when powered. This is quite surprising, as it is not documented in the user's guide. It seems to be a safety feature ("Power-on Beep", that cannot be turned off without the CC Castle-Link.

Now I'm waiting for some calm weather to make sink rate measurements

I did some testing with the Merlin, with the Tuning Propulsion set (Himax C 2212-1180, MULTIcont BL-20 S-BEC, 8“ x 5“ prop).

I did testing with 1 step flaps (ailerons about 4mm down), no flaps, and full flaps (8 mm down).

AUW of plane, without batteries, is 290g. In 2S, battery is 450 mAh (about 30g), and 3S is 450 mAh (45g).

The last graph was taken during the weekend, when thermals where very powerful. From the climb rate (1 step flaps), it seems the thermals were +1.5 m/s !

It seems the best performances are reached with 1 step flaps, for climbing and sinking.





...Continue Reading

First real AP session with Gaui 330X-S.
The camera mount is perfect to remove vibrations.
AUW is 1 kg, and the Gaui handles it perfectly.
It is difficult to estimate height, but I think the highest picture (#2) was taken from about 12 m high.

After more than a year, I'm back at doing AP, this time with a new platform.
It's a Gaui 330X-S, an incredible beast, very stable, and able to takeoff and land in a very small space.
The camera was simply affixed to an aluminum stand, itself held to the quadcopter frame with velcro bands ! This was simply an attempt to try shooting, I will have to build a better frame. There are very limited vibrations, compared to what I had with the TRex 450.
The Gaui 330X-S quadcopter is very easy to fly, much easier than a helicopter because it is stabilized in all axis with gyros. With some trimming, it is possible to have it hover without any control for many seconds, even with some wind. It is also very powerful, and can carry almost twice its weight in payload, with around 10 minutes autonomy. There are no moving parts (apart for the 4 motors and props), no servos, so the window for parts failure is small. It is also much less noisy than a helicopter (as the props are "real " props, optimized), and much less dangerous I think. It is even possible to protect the props with some foam, to prevent almost any injury.
I have a lot of fun to fly it, it's almost as easy as a heli in the simulator (RealFlight) :-)

Did 2 short flights, but it was too windy and cold to do anything serious.

Following some very interesting discussions with kevinhines, I decided to try to put flaps on the Easy Star.
Here are some pictures....Continue Reading

Took the Easy Star out, for the first time in 5 months...

Quite cold (4 C), but sunny. I fitted the Pentax A20 with infrared shutter, not the Canon Ixus 860 (wide angle lens is nice, but its not as good optical quality as the Pentax).

Here's the outcome. A friend of mine came by, jogging with a friend of her, and I was able to grab a few shots of them.

...Continue Reading

Here's the data from a real flight: full throttle launch, where power is at the motor maximum transient value (200 W). The Easy Glider can maintain lefel flight, with easy turns, with less than 20 W of power !

Here are some photos of the flaps I just put on the EasyGlider. First flight was not a success: the butterfly makes the plane climb so much, that full down elevator cannot counter, so the plane climbs, stall, dives, climb, stalls, etc. Not good !...Continue Reading

I changed the power drive of my EasyGlider to the following:

Dualsky XM2830CA-10 (55g 200w kv1180 14A best, 19A max)
ESC Dualsky 30A XC3012BA
Cone 40mm ppales 45 taille 12x8, pied pale 8 axe 3, axe mot 3.2
Blades Aeronaut cam carbon 11x4

(actually I just changed the blades from 11x6 to 11x4).

Measured output:
2S 2200 mAh: 13A, 95 W.
3S 1300 mAh: 17A, 160 W.

The overall efficiency is very good in 2S, and the plane has a good climbing angle, with just 90 W of input power, amazing !
With 3S, it climbs very fast. It can be launched at half throttle (6A : 60 W).

Here it is, measured with ZLog on a calm day, in neutral air.
Easy Glider is at 890g (+8g Zlog).

Normal: -0.8 m/s
5mm flaps: -1.07 m/s
5mm spoilers: -0.7 m/s

Climb rate with current setup (110 W) is about 3 m/s.

I changed the power drive of my EasyGlider to the following:

Dualsky XM2830CA-10 (55g 200w kv1180 14A best, 19A max)
ESC Dualsky 30A XC3012BA
Cone 40mm ppales 45 taille 12x8, pied pale 8 axe 3, axe mot 3.2
Pales cam folding prop Graupner 11x6

The measured output is very similar to what is predicted by Motocalc (with 2S Lipo):
16 A, 115 W.
Motocalc adds: thrust 630g, 5700 rpm, Pitch speed 15m/s, 78% efficiency.
The plane can maintain level flight with just 2 A (15 W), at 7.5 m/s (stall speed 5.5 m/s).

This data is very similar again with what is indicated by Dialsky Calc 3.02.

With that prop, it is not possible to use 3S Lipo, because the motor would be destroyed (21 A > 19 A), or throttle should be kept below 70% (17A, 122W, 65% eff, thrust 630g), similar to 2S at 100% throttle.

It doesn't seem possible to use another prop size, and have good values for 2S and 3S.

With this new setup, I was able to gain 120g on the plane, and thus reducing its AUW from 1010g to 890g, and improving the CG position (now spot on 70mm). It feels very light in flight. With flaps, the plane flies very very slowly, and landing is almost done at walking speed !

It seems the CG can be brought further to the rear, as a dive test indicates it is still very much forward.

Next step will be to measure climb and sink rates. Motocalc indicates: 3.4 m/s climb, and -0.6 m/s sink.

Motor: Mega ACn 16/15/5 With 1:3.3 gearbox.
(KV 1800, equivalent KV with gearbox: 550)
Prop: 15x10 Graupner folding prop.
ESC: Phoenix 35

Motor + Gearbox: 135g
ESC: 30g
Prop & spinner: 54g (spinner 42, prop holder 38, motor shaft 4)
total: 220g.

Wing with nano-s: 156g (spec is 115 + 8 (servo) + 10 (ext. cable) = 133g)
Wing bar: 54g
Fuse with receiver: 448g
Canopy: 19g.
2S 2200 Lipo: 129g

Total flying weight: 1010g.
CG is at 58mm.

With 2S 2200 Lipo, WOT is 15A, 115W, 3500 tr/min, 800g traction (all measured).

I need to lighter the plane, with 2S lipo. The stock setup has a 1220 KV motor and a 10x6 prop.
On 3S (10.5v) it will go 11.000 rpm. To have the same speed on 2S (7.5v), KV needs to be 1700.

Here's what Motocalc says:

10A, 70W, 7500 rpm, 400g traction.
With 3S: 17A, 180W, 10000rpm, 700g traction.

Motor: Dualsky XM2830CA-10; 1180rpm/V; 0.88A no-load; 0.09 Ohms.
Speed Control: Castle Creations Phoenix 35; 0.0045 Ohms; High rate. or 30A - XC3012BA DUALSKY
Drive System: Generic 9x4.5in Prop; 9x4.5 (Pconst=1.31; Tconst=0.95) direct drive.
Cone.
Stats: 77 W/kg in; 60 W/kg out; 5.7m/s stall; 7.7m/s opt @ 77% (50:00, 34°C); 8.7m/s level @ 85% (43:05, 35°C); 1.36m/s @ 10.1°; -0.63m/s @ -4.7°.

The full-throttle motor current at the best lift-to-drag ratio airspeed (7.6A) falls approximately between the motor's maximum efficiency current (8.4A) and its current at theoretical maximum output (40.7A), thus making effective use of the...Continue Reading

Another set of measurements of the Merlin sink rate, done in neutral air, at 275g.

No flaps: -0.9 m/s
5mm flaps: -1.1 m/s
10 mm flaps: -1.3 m/s
Inverted: -4 m/s

The inverted sink rate with no motor is difficult to measure, as the Merlin in not stable inverted, and tries to turn upside right.

I did some sink rate measurements with the Merlin, fitted with a folding prop: it's the stock prop setup from the Easy Glider, that has been sitting in the drawers for 3 years ! It fits perfectly on the motor with a prop saver ! The prop size is 9.5x5. It takes the same amps from the motor as the 8x4.3: 7.5A.
Now, the sink rates are:
with flaps: -1.0 m/s
without flaps: -0.9 m/s

Interesting to see that it floats better without flaps !

The climb rate is impressing: 5 m/s !

Here's one video with the Merlin
Merlin
I did some climb and sink measurements, with and without flaps or spoilerons.
Flaps are ailerons down for 4 mm. Spoilers are ailerons up for 4 mm.

No flaps: climb 3.9 m/s, sink -1.4 m/s
Flaps : climb 3.7 m/s, sink -1.1 m/s
Spoilers: sink -1.4 m/s

So flaps really make a difference for thermal (and probably slope) flying.

The plane is perfectly visible at 230m, and can probably be flown up to 300m (preferably under clouds for better visibility).

Here were some measurements I did with my other planes:
- Easy Glider: -0.8 m/s (-0.6 with flaps)
- Easy Star: -0.8 m/s
- Toro 900 @ 270g : -0.6 m/s

So the Merlin is not the best floater around, but it's very convenient: it fits in its box !

I had crashed my two trex 450 3 times in a few weeks
I fixed them, and this gave me the opportunity to try a new thing: instead of replacing a whole HS-56HB servo, replace just the gear, for 10% of the price ! It was very easy to do (a few minutes), and the result is perfect. The servo is like brand new !
For lubrication, I used silicon spray, I hope this will work OK in the long run.
Marc

Typical eLogger results from stationary flight with Trex 450.
Average current is 11.6A.
Pack temperature rises steadily from 25 degrees (outside temperature) to 40 degrees (C).
mAh reported by eLogger (1289) very close to what was actually put back into pack (1284).

In nose-in hover, with some wind, heli started to be too close to me (<2m), and I think some wind gust pushed it even closer. I pushed it back in reflex, and I think I messed up while it was tail-low. Next thing I now it broke in the ground. Not too much damage though: cyclic servos are dead (all 3), ball link between servo and tail rotor is broken, vertical stab broken, and main rotor shaft bent...
Main blades are intact (well, they were beaten *before* !), as well as gyro. Good !