Nitro Gov setup

As there are some customers asking how to set up a nitro basically right - we want to explain some things here. Please mention that the most important setup values are "static" ones:

  • throttle endpoints (as usual)
  • idle (of course)
  • basic throttle
  • collective add
  • min limit
  • runup limit
  • Auto (Bailout) throttle

That's all - and now lets walk through them ;-)





Here we have the basic diagran which shows dependencie of collective and throttle. Keep in mind that our zero degree point must not be stick center - it can be set up on the tail section e.g. for a scaleship.

The idle is at the bottom of course - and motor stop is the bottom line as you know.











This diagram shows the dependencies of the values in a manaul spoolup mode which is w/o gov. This mode can be used for our basic setup very easy - and so we'll come back later on this.

Basic throttle will be used to set up the headspeed at zero collective - and the collective add should be dialed in to keep it the same at a hover. Both values are banked.








In a flight bank we always use a 3-point v-shaped throttle curve which is determined by the named values here - if the gov is not running (e.g. disconneted rpm sensor).


For setting up this values we suggest to use the method for the spoolup mode above - it will give the same values and the control loop is disabled by default there.








In addition to the drawing above - when the governor is engaged (which means the throttle has passed min limit and a valid rpm signal is given from the sensor) - the throttle curve will be shifted completely by the integral. The goal is to get the right height for the requested headspeed. If the TC is set up too high (too much basic throttle) the rpm overshoots first and will be taken back by the integral afterwards.







Our main control loop parameter in governed operation is called the "Gain". This is a proportional gain, a short term value. Too much will get oscillating rpm effects, too low - no constasnt rpm on the rotor.

To limit the used throttle range for the gain - we have the P Limiter + - see drawing. Downwards - the complete range is used unless we come to min Limit.

On a nitro it may be better to accept a bit higher min Limit (ans so Motor overspeeding on descends) to have enough power for the next collective punch ;-)

















Now - how to tweak them:

Basically - all settings can be done in the Spoolup Bank very easy:

  1. Enable spoolup Bank1
  2. stick down to full negative!
  3. turn the motor on
  4. Spoolup until you have zero collective
  5. measure Headspeed (watch VBar Control display)
  6. dial basic throttle unless you got the HS for your first RPM
  7. go into a hover
  8. dial collective add unless the headspeed seems to be the same (just listen)
  9. write down values and repeat point 4-8 for every one of the max. 3 headspeeds
  10. turn the motor off
  11. dial in the values above corresponding to the target RPM and bank
  12. set min limit approx. 20 points below the lowest basic throttle - but at least 10 points
  13. turn the motor on
  14. stick at zero collective
  15. flip the motor switch to run
  16. if the spoolup goes too fast - lower the gov acceleration limit (default 3) to 2 or 1. But lowering this will lower also the autuortation recovery acceleration.
  17. get into a hover, switch all rpm's to try
  18. on the lowest RPM do a climbout and fast descend
  19. if the motor (not rotor) overspeeds - lower the min Limit. If it has too less punch on the sudden collective input - increase the min limit. It is better to accept a bit overspeeding than have no power ;-)
  20. test autorotation bailout - we would set the throttle for this somewhere between min Limit and idle. Lets say 5-10 points less than min limit - but not below 5 or 10.

That's it!