I've been battling issues for a long time trying to get the gov to work on nitro and I think it's time to give up and just run curves.

I have checked absolutely everything a million times over, replaced sensors, servo, wiring, magnets, everything.

I can only conclude that there is an issue happening in the spirit pro's own calculations.

In the past I had holding performance issues with bogging badly (no bogging, same tune, on curves). Now I have a different problem.

With even default gains of Response: 5 and Holding: 1,

The unit is spooling the heli up to a RPM higher than requested and holding it there. For example in IU2 I have requested RPM set to ~1950, and some of the time the heli spools up to the correct headspeed, and then a few seconds later the headspeed increases and is holding at 2070 instead. I can see the RPM readout on my DX9's telemetry, which is coming from the spirit itself, which means the unit knows what RPM it is running the engine at even though it is the incorrect one. I have no explanation for this. Other times the RPM is holding to the correct headspeed. Then if you land, spool back up (soft start) it creeps up past the requested RPM and holds it too high all over again.

The RPM reading via telemetry is very stable and the numbers look to match what I hear and see from the helicopter.

I tried decreasing response gain, increasing holding performance, and many combinations, I have had issues with this for years now.

If anyone has any suggestions left, they are welcome, but for now I am going back to curves where it all runs properly.

The logs just say 'governor engaged'. No errors or anything weird.

Also calculations in the software seem slightly off as 61% of 3100 is 1891 but the software says 1882, and the correct throttle % (61) does show on the diagnostic screen. But even though it is requesting 1882, it is holding at 2070.

The helicopter is an align 700N with YS 96 srx engine. Align magnetic RPM sensor, I tried three of them and the current is brand new. Brand new magnets in the clutch bell, one magnet is active, sensing divisor is 1. Gear ratio is 8:1. Max headspeed is set to 3100 @ 100% so that I can keep the flat throttle curves low enough so if the governor fails my engine doesn't over rev. Iu1 is 58% and the RPM stays around where it should be, Iu2 is 61% (which should be 1891 rpm,) but it's shooting up to 2070 instead). IU3 is 65% but as soon as I flipped into that it shot over 2100 so I hit TH.

Do I maybe have a defective unit?

I should specify that I am spooling up straight into the governor and not with a normal mode. Throttle hold is 9% for idle and IU1 is now 57% flat curve, IU2 is 60% flat, and IU3 is 62% flat, with 'max RPM' set to 3250.

Sensing Divisor is 1, for one active magnet.
The magnet is reading properly in sensor tester and showing RPM properly in the governor screen as well as telemetry from the 4649t/spirit integration with no signs of dropout or excessive noise.
Gear ratio is 8 (align 700N DFC, 14t pinion and 112t main gear). This is 100% for sure correct.
The servo arm is identical on the throttle servo and carb, so that the arms are parallel in all positions.
Throttle range is set up properly from 0-100%.
Carb physical travel is set to match the closed low and high marks and also has been checked by looking into the carb opening to ensure these marks are correct without extra travel that does nothing physically.

I am out of ideas. Should I reset the unit and do the setup all over again? I would be happy to have somebody take a video of what is happening if that helps. The logs say: governor engaged and nothing else.

Hello,

thank you for all the details .

I would like to ask you if you are spooling up the motor without switching a Banks - from idle.

In theory RPM can increase over Requested headspeed if collective pitch is out of center. Otherwise if you are moving with the stick up and down throttle will increase similarly as with a curves.

It look like we will have to buy the same motor and find a proper settings. Unfortunately there were many other things that are more important for the most pilots so we are focusing on it. But whenever there is time we are playing with the rest.

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Spirit System developer

I am spooling up straight into the governor (start up in throttle hold where it idles, 9%) Release throttle hold straight into a flat curve (57, 60, or 62%). Soft start works properly. Logs say governor is engaged.

The pitch channel is properly set, with 0 degrees physical pitch matching the 50% throttle point in the diagnostic screen and 0% on the pitch channel. The carburetor on the YS engine has a tick mark at 40% for hover. These engines require a significantly lower throttle % in a hover than OS engines, around 10-15% less. I have no idea if that some how may be causing issues. If governing engages at over 50% signal on throttle, is the governor still able to use the full range of the carburetor endpoints to control governing, or does it never go below 50%? If it doesn't, that could be part of the problem.

Hi,

the full range of carburator is not used to not shutdown the engine But also it is not going much under setpoint for hovering RPM, similarly as when using V throttle curve.
We will get the same motor and helicopter to test with then it will be very easy to help.

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Spirit System developer

Sounds good. I ended up putting a MultiGov pro on the helicopter, without changing any endpoints on the carb, and it works perfectly so there is no mechanical or setup issue. From what I hear a lot of fbl governors struggle with YS engines.

It's worth noting that the 96srx has a non-linear throttle response which is probably one of the reasons it has issues with the governor and that people have had this same overspeeding issue with the Vbar governor. The mutligov pro seems to handle it though.

I have to keep holding response on the low side (1 or 2) to avoid excessive overspeed of my YS96SRX. I don't have any other complaints about the Spirit gov with this engine.

It was kind of working at 5 response 1 holding until I did some punch outs and then it went right back to shooting and holding the RPM at 2100 instead of 1950. Some times it spools straight into a higher headspeed though, I actually took a video of this when I was at IRCHA.

A few firmware updates ago I could have holding performance at like 5, but the problem then was bogging in prolonged moves like loops, hurricanes, etc. but I did have it working somewhat for a little while. Without changing the tuning at all, running on throttle curves instead of using the governor, the bogging did not happen, as it was not a tuning issue. I've run the 96srx at anywhere from 2 out on both needles when it's colder to where it is now, just under 2 turns on mid and 1.8 on high. It runs very well there.

I have another YS 96srx in my goblin 700 nitro and though I can't come to any conclusions yet because I haven't done any real flying with it in a while, testing in my yard, hovering, a pitch pumps, etc. it seemed to be working properly with the governor. But again, I will have to actually take it to the field and fly it to see if it still works right; but even just in my yard It was not behaving the way my align 700N did. The goblin was going into the correct headspeeds and at 5 response 3 holding it was holding very well and not overspeeding like the align. I wonder if the belt drive puts just enough extra resistance on the engine that it helps it to maintain speed better.

If the goblin ends up working properly at the field then I am going to conclude that there is something wrong with the spirit pro unit that is on my align 700N. That same unit disconnects randomly when hooked to my computer (the others do not) and also integration with the 4649t does not come up more than half of the time when I power it up.

In any case, the multigov works on the align 700n so it is not an issue with the equipment on the helicopter itself (rpm sensor, engine, servo, etc.).

What is your flying style?

3D and big air. Heli is a Trex 700NDFC with Spirit Pro, Geolink, YS96SRX, Align sensor and 2 active magnets. Spektrum radio with all 3 flight modes governed.