Niki's Betty in English

Niki's Betty (Polyhedral/Aileron/Flapperon)

Airfoil		Polyhedral/Aileron/Flapperon
	Wing length	1500mm
	Profile	SD7037
	Wing area	24.5 dm2
	Wing loading	12 g/ dm2
	Structure	Molded frame and OralightT
	Portability	2 piece wing 2 bolts

Tail plane	Profile	flat
Tail plane	plane area	2.29 dm2

etc.	Total weight	260-300g
	Radio gear	2 Servos (4 servos for Aileron,Flapperon )
	Fuselage Length	1,000mm(up tail trailer edge)

Niki (Nikolay Nikolov) is the designer and manufacturer of this beautiful and robust model. The series of models are known by name of "Highlight". He loves his models just as his children. He calls this model shown in above pictute, Betty by name, who is his daughter. Though he said "please put your own names, which will be more suitable for the Japanese market", I wish to call this model Betty by name and call the series of his models by name of "Niki's family".

Designer
/Manufacturer

Nikolay Nikolov / EtNan (Bulgaria)

Price/Reseller

Northeast Sailplane (NSP) (USA)
RC-Sailplane.com (Japan)
TUN modelbau. (Switzerland )
Frankenmodellbau (German)


Sophisticated form	Enjoyable under weak upwind	Supreme fun in the mountain

Betty front view	Betty Side view	2 piece Betty wing : convenient to caryy by car

Carbon Peg for Hand launch	Fuselage nose like Eagle, Cool!	Wing mount: two plastic volts that reduce weight.

Radio gear: 2 microservo, if you can install switch, then it is convenient.	Rear view: The horn of microservo is exploited.	Conventional tail version

Rear side view. The contact line of V-tail and fuselage should be reinforced by microglass cross.	Adhere two tail planes using Epoxy and miroglass tape at the bottom of v-tail	V-tail is reinforced by Carbon rowing.

Betty Flapperon	Betty /Aileron with Carbon-Kevlar fuselage	New Carbon-Kevlar Fuselage

Wing:

The Airfoil of the handlaunch glider requires careful treatment when it is carried by car in usual, because it is easy-broken in stead of lighter flying weight. The Betty has very robust airfoil. The leading and trailing edges of Betty are all composite and are refined for lightweight and maximum strength. In fact, the airfoil had no damage, when I dropped airfoil on the asphalt pavement. In addition, two pieces wing is very convenient for carrying by car or backpack.
The Betty is not a competition model for the Hand Launch Glider (HLG) , because it is not so light comparing with other conventional HLG. However, once the Betty get a thermal, it can be lifted up to the high place. In the Northeast Sailplaneweb site, This airfoil is introduced as follows;

"The real beauty is in the wing construction. Free flight building and experience is evident in the Omega and it is obvious the designer knows how to make a very strong and light structure. They are also able to build an undercambered wing with accuracy rivaling a molded wing. The molded carbon D-box is molded then foam is inserted for added strength. This D-form is pressed with a layer of carbon into a female CNC machined mold. This gives a very stiff and accurate leading edge for perfect airfoil shape at the leading edge, the most important part for the wing.. The rear of this D-box is faced with some light balsa shear webbing. The middle of the wing is traditional selected balsa build up. Root and transition ribs are made of balsa/carbon sandwich. The trailing edge is molded Carbon fiber foam sandwich and holds the shape accurately also resulting in a very sharp trailing edge for minimal drag. "

(1) Polyhedral Version: It is the standard version. Because no servo is in the airfoil, it is designed to fly at the lightest possible weight without sacrificing strength among three versions. If you fly the Betty by handlaunching, it is the best version. It goes about 30m high by throwing.

(2) Aileron Version: Aileron covers the half of wing tips. This airfoil is polyhedral at the end of aileron and center. Therefore thermaling is easier than the Betty Flapperon. The wing is heavier than the Betty Polyhedral due to the servos and wire. See above picture (Betty Aileron)

(3) Flapperon Version: The wing becomes a little heavier than Polyhedral version due to the two servos and wires. There is dihedral only at the center of the airfoil. The Betty/ Flapperon is called by another name of Highlight Acro 1.5m. See above picture (Betty Flapperon).

Fuselage:

The fuselage is Kevlar and carbon rowing, which is very stiff and light. The new fuselage is made of Carbon-Kevlar cross shown in above picture, which is lighter than the fuselage of Kevlar with Carbon rowing. But the antenna must be put out of fuselage. Both old and new fuselages are quite stiff and strong. The V-tail is coated by the Glass fiber reinforced by Carbon rowing. See Above picture. The two wing pieces has already angle precisely cut and should be contact using Epoxy The portion at the center line should be covered by thin micro glass as shown in the above picture.
The fuselage length of current Betty series is 1024mm. In the Hubschrauber (Germany) website, The fuselage length was specified 800mm for Highlight acro 1.5m. The current version is 1024mm longer than before. But it does not seem to be too long.

Flight:

All of models are very strong. It is possible that all model may launch by F3B winch!. They were not jackknifed. The carbon joiner at the center of wing is very strong and D-box structure makes it very stiff. However Niki's family is made for those who enjoy to sport in the nature with seeking thermal. Therefore the Betty should principally be flied by hand or Bungee code except Flapperon version.

(1) Betty Polyhedral: It flies very stably, and is the easiest model. It goes up to about 30m high by hand launching. I think A little heavier is the better for getting initial height. Total flying weight is 280-320g depends on the radio gear and battery. The gliding ratio is comparatively large. It can reach to about 150m of the horizontal equivalent distance. We can enjoy flying without considering any breakage of the model. It is very important. I have flying the Betty for three years so far.

(2) Betty Aileron: Betty /aileron should fly on the slope or launch by the Shock (Bungee) code to acquire the initial height. The flying weight of the Betty/aileron will be 350g. It is hard to launch up to high height by hand. The Betty /aileron is the good trainer to train to fly aileron model. It's Polyhedral is not so steep. It is recommended that Aileron may be used to modify only attitude. In other words, Aileron-Rudder mixing should be less than 30% or none. In usual, If the fin area is too small and dihedral is large, a "Dutch roll" or lateral oscillation results. The fin area of Betty is adjusted to be able to cancel such a Dutch roll. When aileron is low position, aileron will be a kind of break and the adverse yaw will increase. In order to cancel out it, Rudder should be linked with aileron with appropriate rate and differential aileron should be used. The 8 Channel transmitter can easily program such mixing.

(3) Betty Flapperon: The Betty Flapperon is a sloper or Electric motor should be used. For this purpose the servo for flapperon must have large torque and if possible, metal gear. When it dives from high place, such long flap will cause flattering and break servos in the high speed range. As explained above, the Betty / Flapperon is called by name of "Highlight ACRO 1.5m". There is a brother , named Nelly. It is called "Highlight ACRO 1.8m" Both version has long flap, it is an idea considered to cut flapperon into two. One is aileron and the rest will be flap using 6 servo. Some my friend make Betty/Flapperon be 6 servo model. It is not bad. The Betty /Flapperon has small dihedral. It is for enjoying control technique like acrobat.

Technical Notes:

The Kevlar is very strong fiber that is developed by two scientists in Dupont. There is a good introduction in the Dupont Web site