# How to adjust helicopter parameters, helicopter model version 1

## 0 General information

Please read this file for a description of helicopter parameters.

Please pay attention to these notes.

## 1 Suggested steps

It is assumed that values for mass and inertia already are correct.

1. Before you edit the file, create a backup so you can lookup its original parameters.
2. Set `adjust` to `1` in the opening line of the `config` of the model file you want to tweak:

         <config version="1" adjust="1">

3. Start CRRCSim, set wind speed and thermals to zero (there may be presets you can load).
   Load the model you want to adjust. Save settings.
4. Hint: easiest way to edit/try parameters is to just 'ESC' (to stop the sim), edit and save parameter file, hit 'c' to reload parameters, 'ESC' (to start the sim).
5. If `power.fixed_pitch` is set (fixed pitch heli), adjust `power.automagic.F` to set maximum climb rate.
6. For a collective pitch heli, adjust `aero.cp.ctrl` and `power.automagic.F` to set maximum climb rate.
7. If `aero.cp.auto_off` is not defined or set to `1`, you don't need to care about `aero.cp.off`. If you don't like climb rate at neutral stick as it is automatically adjusted, set `aero.cp.auto_off` to `0` and adjust `aero.cp.off`.
8. Set `adjust` to `2`, which enables tail rotor simulation.
9. If the model has a heading lock gyro, set `aero.yaw.HeadingHold` to something greater than zero (maybe start with 5).
10. The automatically adjusted mixer 'throttle or pitch to tail rotor' doesn't take into account dynamics (changes). You may calm down the tail on changes by setting `aero.yaw.moment_mul` to a value smaller than one (which is the default value).
11. If you are done with the previous steps, enable training mode (hit 't' to enable/disable) to fix the heli at a certain altitude. Set `adjust` to `3`.
12. Unless you know the model and its behaviour very good (in this case there's no need to read this help), remove `aero.pitch.damp` and `aero.pitch.dist` if they exist. They are taken from `aero.roll.damp` and `aero.roll.dist` if they don't exist.
13. Adjust `aero.yaw.ctrl`, `aero.pitch.ctrl`, and `aero.roll.ctrl` for full stick rotation rates in rad/second.
14. Adjust roll damping: `aero.roll.damp`.
15. Adjust yaw damping: `aero.yaw.damp`.
16. Do you think pitch damping (`aero.pitch.damp`) should differ from `aero.roll.damp`? If this is the case: define and adjust it.
17. Does the heli rotate around the correct point? Adjust its center of gravity. I'm sorry, but this setting won't get reloaded by hitting 'c'. You have to save all settings, exit CRRCSim and restart.
18. If you are done with the previous steps, set `adjust` to `4`.
19. Adjust disturbances: `aero.roll.dist` and `aero.yaw.dist`. You may want to tweak `Disturbance.tau_filter` and `Disturbance.time`, too.
20. If you are done with the previous steps, disable training mode (hit 't') and finally set `adjust` to `0`.
21. Fly around and adjust `aero.yaw.vane`, `aero.pitch.vane`, and `aero.speed.damp`.
22. Adjust increase of disturbances in ground effect: `GroundEffect.dist.mul`.
23. Finally, you may want to tweak `aero.roll.ForwardToRoll`.