Airplane
Max Bee Two (A derivate of Igor Burger’s Max Bee 2011/12)
T/O weight: 65 oz or 1’842 Grams
Area (wing & flaps): 691 sq.in or 44.6 dm2
Airfoil: Trivial Pursuit with nose radius 5/16“or 8 mm d max = 2.44 in or 62 mm
Turbulators (4): at 10% of mid wing chord, parallel to LE. 0.02 x 5/16 in zig-zag 20in long
Empennage: Crossfire Extreme
Stabilizer A.o.A.: +/- 0°
Motor thrust angle: + 1°
Motor axis above wing c.l.: 1.4 in or 36 mm
Stabilizer c.l. above wing c.l.: 1 in. or 26 mm
Roll trim: outside tab
Rudder: Adjustable
Lines: 0.015 (0.38 mm) x 64 ft or 19.5 m (eye-eye)
Power Train
Motor: AXI 2826/12 760 KV with cooling fan COOL1
ESC: Castle Creations Phoenix ICE lite 75 A Firmw. V 4.02, & Castle Link V3.55.00
Mode: Control Line / Brake on, high governing mode, Auto-Lipo off (for anti spark plug), Cutoff set to 15.0 V
Timer: Will Hubin FM-9
Programmer: Will Hubin FM-9 Programmer Version 2011, with New Phoenix High Gov. Mode.
Battery: Thunder Power Pro Power G6 5S1P 2’700 mAh 65C 12.7 oz or 370 Grams
Spark protection: Jeti 4 mm female on + of all batteries. – battery with 5.5 mm female
Propeller: APC 13 x 5.5 EP (Thin electric pusher)
Power Train Setup
RPM: 9'553 RPM
Speed: Laptime 5.35 sec on lines: 0.015 (0.38 mm) x 64ft or 19.5 m (eye-eye)
Motor start delay: 30"
Flight time set on Hubin programmer: 5’30“
Time elapsed at end of roll-out (from depressing START button): 6:25
No wind battery recharge: 2'030 mAh (74%)
Final Flight Trim Setup
C.G.: 7.8 in or 199 mm. from hingeline forward (approx. 14.5% MAC)
Leadout centre: 1.42in or 36 mm. rear of C.G.
Tip weight: Outer tip 1.48oz or 42 Grams heavier
Flaps / Elevators throw ratio: 1:0.8
Hinge seal: None
Nose trim weight: 0
Tail trim weight: 0
Roll trim tab: 3° up
Rudder: neutral
Flight Trimming Process
April 2013: Insufficient tracking quality (wandering off from initial height) both in level and inverted flight.
June 2013; Trying to improve the quality of tracking in level and inverted flight, the following modifications (one by one but not necessarily in this order) have been done:
C.G. forward to 7.9 in (201 mm) from hinge line
Lead out center 1.67 in (43 mm) behind C.G.
Flat plate flaps TE rounded (was sharp edged)
Needle sharp elevator TE rounded
Replaced Max Bee empennage by the empennage of Crossfire Extreme, installed at +/0° AoA
Motor thrust axis set to +/-0°
Replaced Rabe rudder by an adjustable one
July 6th 2013: Still suffering from altitude hold issue in inverted flight (no wind).
July 27th 2103:
Added 20 in long zig-zag turbulators at 35% of wing chord.
Changed flap-elevator throw ratio to 1:0.8
Set motor thrust axis to +1° for pusher.
C.G. at 199 mm (7.8 in) from hingeline.
Leadout center at 151 mm (5.9 in) from hingeline, 1.6 in rear of C.G.
Outer tip 52 Gr (1.8oz) heavier than inboard tip.
Tracking improved, better level than inverted. Setup list updated.
August 6th 2013:
Removed turbulators at 35% of wing chord
Added turbulators at 1/2 in from stab leading edge
Tracking not as good as with turbulators at 35% of wing chord
August 10th 2013
Removed turbulators from stab
Added 20 in long zig-zag turbulators at 10% of mid wing chord, paralell to leading edge
Removed flap hinge seal
Removed 10 Gr / 1/3 oz tip weight
Lead out centre 1/4 in / 6 mm fwd.
Tracking ok, better than with turbulators at 35% of wing chord. Set-up list above updated
Peter Germann