Thursday, February 20, 2014

Building the fuselage

The fuselage will hold the receiver, life battery and the 4 servos. Once is ready I will move to the wings that are easier as I am used to f3j building.


Rudder and retract install. A better and cleaner install for the retract than the way I did is to make a metal base for the servo and  attached it to the landing gear plate and not glued against the fuselage.




The Glider and equipment

    Yes it does flex, but quite  a sight.
 
    The Nimbus-4 family is a direct derivative of its predecessors at the highest performance end of the Schempp-Hirth product range, the Nimbus-2 and Nimbus-3. In total as of 2010, 44 single-seat and 100 two-seat models had been produced. The wing has a multi-tapered planform and the wingspan was increased to 26.5 meters. The aspect ratio is 38.8. The fuselage was also lengthened, and a larger rudder was fitted.
The manufacturer claims this glider has a glide ratio of better than 60:1 at a best glide airspeed of 110 km/h (59 knots), meaning it can glide over 60 kilometers on course for every 1000 meters of altitude lost in still air.[1]

The HKM Nimbus is a 1:4 scale with 6,6m wingspan with 4 piece wing to make the transportation easier and 8 servos on the wings (4 ailerons + 2 flaps + 2 Spoilers).




On the fuselage there are 4 more servos (elevator, rudder, retract and tow release) making a total of 12 servos

Two options for radio installation
    a-) regular install with 12 ch receiver (11ch can be used if rudder in  Y)
    b-) JR X Bus clean install

For the X Bus, there are several options that can be used
  1-) one X Bus 7 channel receiver and x bus expander (1 for each wing) and fuse servos directly on the receiver.
  2-) two X BUs channel  for redundancy and clean install

Tx hummm, a few good options
 1-) JR 12x - great radio ! The nimbus is the perfect thermal machine and +2 hours are easy to achieve...NO telemetry ?

 2-) JR XG8 - light, X Bus can handle the 12 servos and much, much more, telemetry gives you the piece of mind for that 2 hours flight, also battery consumption, altitude and future variometer. NO 4 aileron configuration on the glider menu. Why JR, why ? Probably can make it work with p-mix, but not an easy task and it wont be 100% perfect.

3-) JR XG14 - All of the above plus the 4 aileron configuration on the glider menu. Perfect, need to get one.

The glider killer: power supply !
  Most of the fatal crashes that I have seen were due to battery issues, so redundancy is a must. Encontec mini handles 2 life batteries and it is light (don't wont to end with a heavy glider), Power box new gemini 2 is also a very good option. Two life of ~3.000 is plenty.