|Kappa 25 Specifications|
|Wing span||2.5 m||98 in|
|Wing area||38.7 dm2||600 sq in|
|Length inc spinner||122 cm||48.0 in|
|Flying weight from||760 g||26.8 oz|
|Wing loading||19.6 g/dm2||6.4 oz/sq ft|
|Spinner Diameter||32 mm|
|Centre of Gravity||68-71 mm from wing leading edge|
|Controls||Rudder, elevator, ailerons, flap, throttle|
|Kappa 25 Typical Weights|
|Fuselage||87 g||3.1 oz|
|Glass layup wings||386 g||13.6 oz|
|Tail Plane||13 g||0.5 oz|
|Fin||13 g||0.5 oz|
|Accessories & glue||18 g||0.6 oz|
|Total structure||517 g||18.2 oz|
|Wiring||10 g||0.4 oz|
|Pushrods||9 g||0.3 oz|
|Receiver||8 g||0.3 oz|
|Rudder servo||5 g||0.2 oz|
|Elevator servo||5 g||0.2 oz|
|Wing servos (4)||40 g||1.4 oz|
|Speed control||34 g||1.2 oz|
|Motor||45 g||1.6 oz|
|Prop & spinner||20 g||0.7 oz|
|Battery||67 g||2.4 oz|
|Flying weight||760 g||26.8 oz|
|Rudder & Elevator||Ripmax SD100, Blue Bird BMS-101HV, KST X08, MKS DS65K, MKS DS75K|
|Ailerons||Ripmax SD100, Blue Bird BMS-101HV, KST X08, MKS DS65K, MKS DS75K|
|Flaps||Ripmax SD150, KST X08, MKS DS75K, MKS DS6100, MKS HV6100, Hyperion DS09-AMD, Corona DS843MG, Blue Bird BMS-105HV|
|Kappa 25 Powertrain Recommendations|
|Powerline Micro 1015||3S 800mAh LiPo, 15x8 prop|
|Powerline Micro 1010||3S 600mAh LiPo, 12x6 prop|
|ADH300L Front Mount||3S 450mAh LiPo, 9x5 folding prop|
|ADH300L Front Mount||2S 450mAh LiPo, 11x6 folding prop|
|Mega 16/15/4 direct drive||2S 800mAh LiPo, 10x5 prop|
|Dualsky XM2826CA-10 45g outrunner||3S 800mAh LiPo, 10x7 prop (19A, 5.0 m/s)|
Review by: DerryReview from Australia
I have only just completed the model and had half a dozen trimming flights. The Kappa arrived at my home in Queensland, 10 days after ordering, which I think is brilliant, well done HyperFlight, some Australian company’s cant process and deliver an order to me in that amount of time.
The model was removed from the box with much anticipation, no damage, plenty of bubble wrapping had been used for shipping. The workmanship and finish of all the model parts is excellent. I have just returned to modelling after 25 years and I have never owned any thing like this before, so I spent a couple of weeks looking and planning before I started the build, thinking "would have liked a basic set of construction details etc with control throws, etc.". Google to the rescue.
She went together easily after deciding the position of the fin and rudder. a bit of a grey area, found photos on RC groups, of fin and rudder mounted on top of the boom and some with the rudder extending to the bottom of the boom. Went with the second option. Cut the boom to give me 1200mm to the LE of the rudder and then extended the rudder down to the bottom of the boom. Possibly wrong choice, she came out tail heavy, even with a rearward CG of 75mm. I have 22grms of weight taped to the back of the esc. All motor / esc wires were shortened as much as I could and the battery is pushed as far forward as it will go. I used 1mm carbon fibre inside PTFE tubing for the rudder and elevator pushrods. R&E servos are fitted at the rear of the hatch area is a fiddly job.
Wing servos were then wrapped in tape and then glued in place with ply servo frames. I went a bit overboard and epoxyed in some extra small blocks around the servos. The wing wiring harness was soldered up to the mini deans plugs with a lot of swearing, not a job I enjoyed. The receiver aerials were exited - 1 thru the top and 1 thru the side of the fuse. With everything mounted including the extra 22 grms and battery she came out at 870 grms - a little over weight. my servos, esc, motor and battery are heavier than the items in the model spec sheet.
The radio - Futaba 10j - was programmed as per full house sailplanes and with the motor on a switch. Spent a week looking and checking and double checking then down to the club field.
Range checked out OK.
Cool, early morning, no breeze
A good firm hand launch, no motor, she just flew straight out and kept going.
no control inputs until a flair to land.
Next, turn on the motor and launch, needed down to maintain a steady climb, climb rate was good, all control throws were to much, first flight was just over 4 min.
The next five flights were used to check and adjust control throws.
I am very happy with the way Kappa flew, and she will only improve as I continue with the tuning process.
Gear used: Dualsky eco 2216 Kv 980
Motor: Hyperion G7- 900 x3s
Esc: Hefei 45a.g
Servos: Ail / Ripmax 150, Flap/ Corona, R&E / Hitec HS45hb.
I am not happy with any of the servos I used / they do not centre very well. Apart from that I am very pleased with the plane.