Recently installed Spirit RS on a Trex 700 gasser (23cc Vario). Somehow there is some kind of drift in stabilisation modes: swash plates creeps forward or backwards during flight. This means I have to give incrementel amounts of elevator to keep the heli level. If I land the heli in this situation, the swash is tilted backwards or forward. Sometimes it works okay though.

Things I tested:
- vibrations are within normal limits for gasser engine. Vibrations do never exeed 80% and are evenly spread over all axis. Depending on head-speed vibrations will not be lower than 70% in flight (around 15% at idle).
- Rescue mode never failed me and returns to level. Even after multiple flights.
- No error logs.
- Swash is absolutely level and geometry is set as intended.
- Enhanced Signal Processing enabled. (solved tail wag issue)
- Problem appears in stabi normal, coaxial and acro. Scale not tested.
- Wires not touching the FBL unit.
- Problem occurs with and without geolink.
- All shafts, gears, and bearings are in good condition.
- Main and tail blades balanced and in track.

Two questions:
- Possible to solve this? Perhaps with special firmware (because rescue works just fine)?
- Will position hold/altitude hold and RTB work without using stabi function? I did not test this because I do not want to crash.

Thanks in advance, Chris

When I was struggling with a vibration issue, I recall using the expert setting 'signal processing' and selecting the 'extended' checkbox. Perhaps that would be helpful? It is defined as being:

http://manual.spirit-system.com/index.p ... T_SETTINGS



In the manual, it does talk about vibrations, here:

http://manual.spirit-system.com/index.p ... NOSTIC_TAB



It makes no note of expecting nitro/gassers being outside of that 50% upper limit, that I can find at least.

Good luck sorting it out.

Hello,

please enable Extended signal processing in the Expert settings.

See this page:
http://manual.spirit-system.com/index.p ... ise_Rescue

_________________
Spirit System developer

Thanks for the replies. I did already enable enhanced processing as stated in the list with things I already tried.

Unfortunately this does not solve the problem.

Hello,

thanks for the message. Are you sure that Stabi Correction is OFF?

_________________
Spirit System developer

Stabi Correction is off.

Hello,

I am very sorry for delayed reply. Unfortunately we are extremely busy at the moment.

If you will be interested we can ship you other unit for comparison. In this way you can make sure unit is OK.

Additionally we are working on firmware improvements to make GeoLink features to work well with any vibration level.
But there are many other things to do.

Could you please send me your current settings?

_________________
Spirit System developer

Thanks for the reply. No problem, I understand how busy some periods can be. To make sure I would be interested in testing with another unit. Notwithstanding, there might be a relation with vibrations indeed. I managed to reduce vibration levels to about 45% the last week, but this did not solve the issue. There were small improvement in stability coaxial, but still drifting after a while. For as far as I can understand firmware solution might be the best suitable, so keep up the good work.

Is it possible to send the current settings by e-mail? Perhaps I can send a save-file of settings of the PC spirit application?

You can just attach it here or send by email. It is 4DS file.

You can also check the Diagnostic tab:
When engaging Position Hold, Stabilisation mode is not engaged. Is this correct?

_________________
Spirit System developer

Stabi, Position Hold, Altitude Hold, RTB are set at different channels. The settings are attached to this reply. Have been testing multiple functions (including GeoLink) past tuesday as well. For testing purposes headspead was reduced to around 1650: this reduced vibrations to 45%. (Not exceeding 52% in flight). GPS test were performd with 12 sats.

- Tested Stabi Coaxial (GeoLink functions off): will drift when hover after a while (tested 7 times). Time before this happens is highly variable (immediately, 30 secs, or after a few minutes). Drift is always forward and always incremental, resulting in having to apply full back elevator to hover in place. At this moment I will always land the model in order to prevent damage/loss of control. Sometimes (2 times in test), flying around seems to "reset" the problem. Other times, drift continues the moment I return stick to neutral.
- Tested Position Hold (stabi off): drifted leftwards (2 times), drifted forward (3 times), more than 5 m.
- Tested Altitude Hold (Stabi Off, Pos Hold off): model drops to ground level (slowly) en keeps altitude at 0.5m after touching the ground (tested: 3 times at 10m, 5 times at 2,5m). Because of this, I tested with Altitude Hold (2). Once in Altitude Hold (1), model dropped instantly (fast) and had to rescue the model manually.
- Rescue (Normal): no issues (tested 5 times, random interval between other tests. For this, I had to land and change stabi function to rescue of course).
- Tested combination of Position Hold & Stabi: same problem.