Circle Dancer 3600 Electric 3.6m

The Circle Dancer 3600 Electric is a beautifully constructed 3.6m span balsa and carbon almost ready to fly version of the Bubble Dancer by Dr Mark Drela. This 3.6m version is an all new structural design, with stronger and stiffer carbon Dbox wings and other strength improvements, but with the same excellent quality of manufacture that makes this model so special. Note we are importing both “full house” (rudder, elevator, aileron, flap) and REF (rudder, elevator, flap) versions of this model. The REF version has increased dihedral, making for a more stable and easier to fly model. In comparison the full house version has flaps and ailerons to allow better roll control and wing camber changes to give the model a wider speed range.

Although the structure is simplified in comparison to the original Bubble Dancer design, the aerodynamics are very similar, and the Circle Dancer 3600 is a stable and easy to fly model with impeccable thermal performance, and a good speed range.

The fine fuselage consists of a lightweight Kevlar, glass, and carbon pod molding with a small pylon for mounting the wing above the fuselage, to reduce interference drag. The fuselage nose incorporates a large (18 cm long) hatch to allow easy access to the motor, battery, and rudder and elevator servos. The hatch is very nicely molded from carbon fibre and incorporates a positive attachment system. The fuselage has been updated to use a molded carbon tailboom incorporating a small pylon for the tailplane/horizontal stabiliser. All pushrods are supplied, along with a complete set of tail hardware.

The tailplane is a feather weight built-up balsa and carbon construction, covered with lightweight transparent film and is supplied ready to bolt onto the rear pylon mount. The tailplane is of improved construction and includes a separate ready hinged elevator for faster pitch response.

The wing is expertly constructed from balsa and carbon, with a strong carbon DBox front part and beautifully applied transparent film covering, in contrasting colours. Unlike the BD, the Circle Dancer 3600 has flaps built into the centre panel and the full house version has ailerons in the tip panels. This gives better control authority (especially when landing in gusty conditions), good landing approach control, and the ability to control the airfoil’s camber to optimise the wing for cruising, thermalling, or flying faster against the wind. The standard of construction is excellent, and the prefabrication is very complete. The only things left to do are gluing the tailboom to the pod, gluing the fin, installing the control surface control horns, fabricating linkages for the flaps and ailerons, and fitting the RC and powertrain.

Check out this useful RCGroups build thread.

Circle Dancer 3600 Electric Specifications
Wing span	3.6 m	143 in
Wing area	79.1 dm2	1226 sq in
Length	175 cm	68.9 in
Flying weight from	1500 g	52.9 oz
Wing loading	19.0 g/dm2	6.2 oz/sq ft
Aspect ratio	16.6
Wing airfoil	AG35/36/37
Dihedral (EDA)	6.0º
Spinner Diameter	32 mm
Centre of Gravity	102 – 106 mm from wing leading edge
Controls	Rudder, elevator, ailerons, flaps, motor

Circle Dancer 3600 Electric Typical Weights
Fuselage	235 g	8.3 oz
Centre panel	473 g	16.7 oz
Wing tips	364 g	12.8 oz
Tailplane	33 g	1.2 oz
Rudder	10 g	0.4 oz
Pushrods, joiners, accessories	83 g	2.9 oz
Total structure	1198 g	42.3 oz
Glue etc	5 g	0.2 oz
Wiring	24 g	0.8 oz
Receiver	8 g	0.3 oz
Rudder & elevator servos	20 g	0.7 oz
Flap servos	20 g	0.7 oz
Aileron servos	20 g	0.7 oz
Speed control	45 g	1.6 oz
Motor	135 g	4.8 oz
Prop & spinner	25 g	0.9 oz
Battery	120 g	4.2 oz
Flying weight	1500 g	52.9 oz

Circle Dancer 3600 Recommended Servos
Elevator & rudder	MKS DS6100, MKS HV6100, KST X08, Blue Bird BMS-125WV, KST DS145, KST X10-710
Flap	MKS DS6100, MKS HV6100, MKS HV6110, Blue Bird BMS-125WV, KST DS135, KST X10 Mini
Aileron	MKS DS6100, MKS HV6100, MKS HV6110, KST X08H, Blue Bird BMS-125WV

Circle Dancer 3600 Control Movements
Rudder	35 mm each way
Elevator	11 mm up, 11 mm down
Ailerons	12 mm up, 10 mm down
Flap	80 degrees down
Thermal camber	flap 5 mm down, aileron aligned with flap
Speed camber	flap 1.5 mm up, aileron aligned with flap

Powertrain Recommendations
Powerline Micro 1025/10	3S 1Ah LiPo, 16×8 prop
Leomotion L3013-4550	3S 1.2Ah LiPo, 15×9 prop
Leomotion L3025-4550	3S 1.2Ah LiPo, 15×8 prop
XPower F2925/8 Windy	3S 1.5Ah LiPo, 12×6 prop
Hacker A20-6XL geared 4.4:1	3S 1.5Ah LiPo, 16×9 Aeronaut prop
Mega 16/25/3	direct drive, 3S 1.2Ah LiPo, 11×6 prop
Axi 2220/12 V2	direct drive, 3S 1.5Ah LiPi, 12×6 prop