Spirit System

Hello Tomas,

I'm going to open a new thread here, as it's probably getting lost in the other thread -
As described before in my opinion it is necessary to start new -

If mostly all parameters are behaveing in an other way then before, then would it be not better to make a presetting of all helicopter sizes, like 450 Class, 500 Class, 600 Class and 700 Class - All parameters would be related to the corresponding heli Class -

I am aware that the settings vary from helicopter to helicopter in the same classes...
These are then maybe not the best settings but an secure and good one for the first flight and thats the most important -

Then it would be also absolutely necessary to explain all single parameter and their mode of action - please do not refer to other documents that makes no sence to me - It is better to do that on one new document so you don't lose track, this will help all users -

I have to say that I am also not so happy because the bahavior is different and I am not shure what to change in the settings -
So I think it would be necessary to to explain it in detail - please give it a chance, the users will thank you for that !

@all users who want to know in detail what to choose to dail in the helicopter, please make an comment here, then I belive Tomas will give us the necessary information !

Best regards
Matthias

Hello,

actually there is nothing different from 3.X firmware regarding parameters and their meaning and purpose. The main difference is that everything was reworked in some areas, but basically only this what was written in the ChangeLog require some adjustment.
New parameters introduced in 4.0.0 are explained in the manual here:
https://manual.spirit-system.com/index. ... T_SETTINGS

Parameter Swashplate Dampening (added in 4.0.0) changed algorithm but its purpose is still the same. Additional description was added to the manual as well (especially for Pitchup Compensation)

All base parameters including Gains can remain same when comparing to 3.X version. Rudder Delay can be also more or less same as with 3.X when using 4.0.1. Pirouette Consistency is same between all versions.
Only Rudder Stopping, Rotation Rates could require tuning, because this changed completely.

Main difference from 4.0.0 is in the Cyclic Feed Forward where it is enough to set 1-2 points lower value for obtaining similar effect as before. This is required in almost all cases. CFF itself works identically as for 3.X, but unit allows much faster response generally. So reducing CFF will help and avoid possible elevator bounce back.

I am not sure if I understand new preselection inquiry. This is already included in the Setup Wizard and require no change.

Timo Wendtland is delivering really extraordinary support for parameter tuning in this thread, i.e.:

https://www.rc-heli.de/forum/technik-un ... ss/page469

It would really desirable to have this knowledge concentrated in an official document. Current documentation is superficial and will not help in cases, where models are not "standard" (i.e. low RPM, scale/heavy, F3C).

Sepp62 wrote: Tue 07. Oct 2025 9:39:54 Timo Wendtland is delivering really extraordinary support for parameter tuning in this thread ...

This is the kind of information that is really missing from the official documentation. The one thing that I always find lacking with Spirit is some of the the parameter names don't help in explaining what they do at all. The guide explains how to tune some things based on subjective feeling but it's not intuitive to understand how things influence eachother at all. I always get the feeling it's trying to be secretive about the algorithm but this is a bit unhelpful especially in a world where Rotorflight exists.

For example I always guessed that "piro consistency" is mostly tail i-gain based on its behavior and manual description but this isn't confirmed anywhere, if it had just said that I would immediately understand much better how to tune it.
Knowing swashplate dampening is increasing i-term decay (possibly based on stick derivative?) is incredibly helpful, but I don't know how it relates to flight style. The name is counterintuitive as well, I would expect high dampening will make smoother stops but if it's suppressing the i-term it could be opposite? Flight style itself is not clearly explained but it appears to tweak the ratios, just guessing here (lower style = greater i in relation to p/d?). What if I use low flight style with a high dampening value, how is this different from high flight style with lower dampening?
No idea what elevator filter is doing either. Manual says it can help with bounce back caused by high cyclic feedforward. It is clear why a high feedforward can induce bounce back, but my intuition in this case would be to reduce feedforward instead. Tuning guide also wants you to tune feedforward first and says too high value will cause bounce back. So why is there another step at the end to eliminate this effect using a different parameter.

I understand there is a balance between exposing more parameters and technical details vs ease of setup. The thing is Spirit just works very good on default settings 99% of the time and this is very important for many pilots. But if you want to get the most out of it you will need to tweak things and then it's very helpful to know what it actually is you are adjusting.