Aztec 2 Step Plus

25 Jul 00 - Photographs updated.

Aztec 2 Step+ - Front Quarter View Aztec 2 Step+ - Front View

N of launches / Time 11 0 hours 41 mins Note: Not all flights included
Wingspan 39 " 0.990 m
Wing Area 290 in 18.7 dm
Flying Weight Unknown Unknown 3 lb. 1 oz 1.40 kg
Wing Loading Unknown Unknown 24.6 oz/ft 74.8 g/dm
Wing Cube Loading Unknown 17.3 - Racer (no wonder it likes to fly fast)
Motor 2 x Speed 400 6v in parallel 2 x Mulitpex Permax 450 Turbo in parallel
Propeller 2 x Tornado 5" x 4" or Graupner 6" x 3" folders 2 x Aeronaut 7" x 4" blades, fitted in the hubs of Graupner 6" x 6" folder
Batteries 7 SAFT 1400mAh 8 Sanyo RC-2000
Speed Controller Gordon Tarling Micro-Star 40BEC/B - 6 to 10 cells, 40A, BEC & Brake
Receiver Hitec HFS-04MI - PPM - 5 channel - 35 MHz
Servos Ailerons - Hitec HS-300BB
Elevator - Fleet FPS-18
Static motor parameters  Multiplex Permax 450 Turbo motors with 7" x 4" propellers on 8 RC-2000 cells - 12600 rpm (average) @ 8.0v drawing 35.2A (17.6A each) and producing 39 oz. (1.1kg) thrust after 30 seconds.
Flight performance Speed 400 6v motors with 5" x 4" or 6" x 3" propellers on 7 SAFT 1400mAh cells - under-powered and difficult to keep airborne

Multiplex Permax 450 Turbo motors with 6" x 6" propellers on 8 SAFT 1400mAh cells - slightly better, but doesn't fly fast enough to unstall the propellers.

Multiplex Permax 450 Turbo motors with 7" x 4" propellers on 8 Sanyo RC-2000 cells - No problem with power now. The model will easily loop from level flight and climbs out at an angle of approximately 15.

18 Jul 00 - Whilst flying today (at about 100' (30m)) the elevator servo jammed slightly with the elevator surface slightly down. The model arced into the ground at ever increasing speed despite me cutting the motors. The fuselage was a real mess, and substantial damage was sustained by the wing. The model is not practically recoverable and will be scrapped. The servo was stripped down after returning home, and I found the gear train jammed. This was freed and the servo appears to function correctly. This servo will now be treated as suspect and consigned to non-critical roles such as throttle / miscellaneous functions.

16 Jul 00 - Managed to get the test flight in today - the model flew really well with bags of power. The only 2 slight niggles. Firstly, that the spinner assembly vibrates & needs to be fitted further on to the shaft. This can be rectified by reducing the shroud on to front of the nacelles. Secondly, one of the ailerons pushrods disconnected itself at some point. I didn't even notice until preparing for the next flight. I will have to fit slightly longer bolts to allow a locknut to be fitted.

11 Jul 00 - I have completed the restoration & the model awaits it's test flight.

10 Jul 00 - I decided that I'd give this model another try. I will be refitting the 450 Turbo's, but using Aeronaut 7" x 4" folding propellers. These are probably much better suited to this type of model than the old propellers.

10 Jan 98 - This model was scaled up, to 133%, from a Radio Modeller free plan published in 1991. The control surfaces are aileron and elevator only with the tailfin finished to give the impression of a rudder. Instead of the original Cox 0.020 motors it was fitted with 2 Speed 400 electric motors with a Ken Hewitt speed controller. The photograph show it fitted with opposed 5.5 x 4 propellers, but later fitted with Graupner 6 x 3 folding propellers to protect the motor shafts. To improve the performance it has been fitted with 2 Multiplex Permax 450 Turbo motors driving 6 x 6 folding propellers. I have retired this airframe as I want the motors for a different project.

[ BACK ] [ INDEX ]