murankar
Staff member
I pulled this tuning procedure from General Tweaking Order | VStabi. This is what Mikado recommends for the initial tuning of a Vbar or Neo.
Some basic infos how tweak main rotor and tail rotor can also be used in the links.
Best preconditions are:
Step 1 - Basic Gov settings:
Step 2 - Basic Tail together with Gov:
Step 3 - Tail gain:
Step 4 - Elevator Precomp:
All steps below can be done in different order:
Step 5a - Trim flight
Step 5b - Swash Optimizer:
Step 5c - Tail Optimizers:
Step 5d - Main Gain:
Step 5e - the rest:
And of course - to be perfect - most of this can be done for each bank.
Some basic infos how tweak main rotor and tail rotor can also be used in the links.
Best preconditions are:
- blades (fold method) are at 0deg in setup (locked) position
- Cyclic Ring set up as best in hover collective point
- Tail throws set in useful ranges
- paddle sim and pitch pump are zeroed
- style is at 70...100
- useful gear/kv/cell count setup for the target RPM
Step 1 - Basic Gov settings:
- Gov Gain to 0
- Gov I to 0
- Spoolup at zero collective
- dial in basic throttle unless HS matches
- go to a hover, dial in collective add unless HS will be kept under hover too
- do a medium climb, check hs, possibly add some collective add again
- set cyclic add to 1/3 of collective add
- turn back gov gain and Integral
Step 2 - Basic Tail together with Gov:
- lower tail gain (e.g. to 40)
- hover and do medium climbs
- on a CW heli - if nose turns to left in the climbs - increase collective torque precomp in tail
- if it stays approx. - the optimum has been found.
- if it still turns although the precomp is e.g. at 60 - decrease (!) the collective add of the governor (tail is overloaded by too hard gov'ing)
- set cyclic precomp to 1/3 of collective precomp
Step 3 - Tail gain:
- just increase ad needed to hold the tail. The VBars have a internal gain calculation depending on the flight situation to avoid oscillations - e.g. in fast flight.
- If the tail holds well - not more gain needed
Step 4 - Elevator Precomp:
- lower main rotor gain to 30-40 (approx 1/2 of the usual recommended gain)
- from a hover - start a climbout
- watch the tail boom. If it hangs down first - increase the precomp
All steps below can be done in different order:
Step 5a - Trim flight
- as the tail torque precomp changes the tail "center" - the TF will be done after the steps above to be perfect
- perform the trim flight on a calm day
- lift off, hover hands off for some seconds, repeat a few times
- if a hands off pirouette stays in place - end trim flight
Step 5b - Swash Optimizer:
- dial in the target agility, this resets the cyclic optimizers!
- do some constant rolls and flips in all 4 directions with approx. 50-70% of the stick throw.
- lets say 5-10 each direction will be ok, turn the optimizer off
Step 5c - Tail Optimizers:
- do some pirouettes in each direction
- also some stops (5 each side will be ok)
- turn the optimizer off
- if the stop is a bit softer on one side (due some physics) - increase the stop gain, see if it helps
- if it won't help - lower the tail acceleration which gives a bit softer response but more equal behaviour (optional, lower down to 45 ans less, often used on weak scale tails with 30)
Step 5d - Main Gain:
- increase unless you won't notice changes anymore.
- not critical - so it is possible to keep it at 80 on a usual helicopter
Step 5e - the rest:
- dial in Style as preferred (low = more smack, high = more precise)
- same with paddle sim
- and pitch pump (but - if using this - the tail will show up the limit again ...)
And of course - to be perfect - most of this can be done for each bank.