One of my nitros has had governing issues for a long time. I've tried 5 different sensors, new magnets, and just about anything else I can think of.

RPM (magnetic) sensor is placed correctly and reading properly under the sensor test. Throttle endpoints are for sure 100% correct, I even checked the carb barrel to see if there could be more physical travel past fully open which there is not.

Once the engine is tuned reasonably I enable the governor for tuning.

Slow spoolup, rampup set to 10u which gives a really nice smooth spoolup for nitro. Starting settings are 5 for governor response and 1 for holding performance as recommended in the manual. 80% for holding limit.

The problems:

First, this is not specific to this helicopter but all of my helicopters, why can we not achieve the correct desired headspeed; for example if I want 1800, 1900, and 2000, I cannot ever achieve these exact values, as no matter what 'max headspeed' is set to, the math is never correct in relation to the throttle percentage I set in my transmitter. I have tried subtrimming the throttle channel and still can't get the 'correct' number. I always get strange values like 1996 instead of 2000, 1883 instead of 1900, etc. The gear ratio is 8.0 so it should be able to have exact calculations. I have always just settled and accepted that you will never get the exact value you want.

Now specific to this model:

at response 5 and holding 1, the RPM readings are pretty close to where they should be (looking at my TX telemetry reading). When spooling up directly into a flat line/governed mode, it will overshoot and then settle into the desired headspeed. The throttle endpoints are 100% correctly set.

If I increase holding performance even one point, the target headspeed increases. For example with response 5, holding 1, if the requested headspeed is ~1700 rpm, as soon as I increase holding performance to 2, it raises the headspeed to about 1740rpm. And if I add another point to holding performance, it will raise even more. The same thing also happens if I only raise governor response. Any change from response 5 and holding 1, ends up increasing my headspeed. The requested headspeed remains the same, but the actual headspeed increases which I can see in telemetry, and hear as well. I have tried decreasing response gain down to 3, where it is noticeably too low, and even then, as soon as holding performance is increase to 2 or anything else over 1, the headspeed increases.

I have also tried reducing holding limit to 70% and this did absolutely nothing to help.

I have tried a multigov pro on this helicopter and it reaches and holds the correct headspeeds with default settings.

The YS 96srx is a bit of a finicky engine in that headspeed drastically increases beyond around 60% throttle. On a V-curve the center must be fairly shallow otherwise it will over rev.

Having said that, the governor seems to work on my goblin black nitro which has the same sensor, servos, and engine. I have no idea what is going on. Tomas, is it possible that this particular spirit unit may be broken? The only thing I haven't tried is swapping one of my other units onto his helicopter. It is worth noting that on this particular helicopter, the telemetry connection with the 4649t doesn't come up half of the time either, and I have to power cycle it a few times to get it to. I do not have this problem on my newer units.

Anyone?

Who is using a YS 96 with success with the spirit gov?

Today I tired the helicopter after doing two things: I moved the servo horn balls in one hole to increase resolution (now there is 870us total travel), and I also moved the RPM sensor to the other side of the helicopter which is the correct stock configuration per manual. It seems to see the magnet for a slightly longer time in this new position. It is very, close to the clutch bell and magnets, for sure position properly. Readings from this position seem more consistent though they were not bad in the other position.

Two new issues came up:

1) After soft spoolup the rpm would overshoot the target RPM and then creep back down to the correct RPM. I have seen this before in the past as well with several of my helicopters electic and nitro. The throttle endpoints are absolutely set correctly fully closed to fully open.

2) In a hover, even with holding gain set to 1, rpm is surging up and back down, in a fairly slow, long pulsing manner. It gets worse when I increase holding gain. I can see this in telemetry and the readings seem to be very accurate.

Response gain however works well and I can see the difference when I increase or decrease it. I see no signs of clutch or one way bearing slippage during pitch pumps.

I understand that this new surging can be something other than the spirit and I am currently trying to find out potential causes. I will test tomorrow on curves to see if it happens on them as well.

I'm running an ic model with a similar setup to you. YS96SRX with align sensor and Spirit Pro. Gov is not the best but works ok with holding performance set to 1 or 2. Intermediate 3D flying mostly.


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And what happens when holding response is more than 2?

The engine will rhythmically surge during hover and overspeed after hard manoeuvres.

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No surging on throttle curves.

It's the spirit gov.

RPM sensor is perfect, giving stable readings. It gives stable readings when I spin the blades by hand hooked to the software to get the reading, and it gives pretty stable readings through telemetry. The headspeeds shown correlate with what I see and hear.

Three years ago I was able to set holding performance all the way to 5 or 6, it just worked poorly and would sag during loops and hurricanes. Now I can't go past 1 without RPM overshooting in a hover or surging. I'm sure that has to do with firmware updates, but still. I tried setting holding performance down to 60% and it was still surging.

Does it just not like the 8:1 gear ratio? Why is it not doing this on my goblin nitro? (granted, it has done similar things on the goblin back in 2018, but it does not appear to be now) The tunes on the engines are nearly the same.

The only thing left is to try a different spirit unit before giving up and putting the mutligov pro back on forever. I would be happy to post a detailed video of everything- sensor placement and distance from the magnets, throttle servo setup, my gov screen in the spirit software, hovering on throttle curves, and hovering on the spirit governor for comparison as well as what happens when I raise gains.

Today I tried a new check valve, all new fuel line, new glow plug, same things happening.

Cleaned the entire carb out. Same thing.

Today the headspeed shot up from a target of 1800 up to 2140 (according to telemetry). If the sensor was not reading properly I would not be able to see in telemetry what I hear and see. Gov response 5, holding performance 1. I even went down to 3 on response, and you can notice it doesn't react as well, but no difference in surging in a hover, governor overshooting target headspeed, etc.

I am totally lost on this one.

There are no rpm signal errors in the logs, no noisy signal, etc. Just "governor engaged" while it overspeeds the engine. (log attached, note I turned off my radio before powering off the model at the end, hence the signal lost).

Everything is set right. Throttle endpoints, sensor is reading perfectly, no issues on throttle curves, and my multigov pro hits the right headspeeds using the same exact servo and sensor that is in there.

Tomas we all appreciate everything you've done with the spirit units over the years and are grateful for all the new features. But please, PLEASE fix the nitro governor. Three years and I cannot get it to play with this engine. Nitro is still very popular here with all the new models that have come out. I don't want to have to remove one of my other spirits to test it on this helicopter but that is the absolute only thing I have not tried.

Brain2 has a nitro setting under the governor menu, an algorithm that works for electric isn't necessarily ideal for nitro.

Hello,

can you let me know all your setup, please?
We will buy more or less same and test it for you.

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Spirit System developer

Sure - YS 96srx engine, Hatori muffler, KST BLS815 throttle servo, align magnetic RPM sensor, this is an align 700N with an 8:1 gear ratio (112t main gear, 14t pinion). Throttle is extremely touchy with this engine- maybe the governor is not used to having to use such low throttle percentages? I'm not sure if the spirit governor algorithms set a lowest throttle value for governing but often times, in a hover to maintain proper headspeed the throttle percentage is in the 50's with this engine- by the time you get to 60-62% throttle in a hover headspeed is around 2000rpm.


Do you think this particular spirit unit may have a glitch? Is that even possible? It does disconnect some times when using the spirit software, and often my 4649t telemetry does not come up without power cyclic it a few times. Not having these issues on my other units. No issues with actual flight though.

I put the multigov pro back on, will test today, but it has always worked properly when I have put it on before.