Totally confused by Brushless Governor

[Mixmaster Pilot]

Firstly - in the gov menu when it asks if I have a analog or digital servo, what do I choose?

Secondly, can the CGY750 actually do a soft start?

Thirdly, in the gov basic menu - Rev. Sens. What should the left hand number be when the motor isn't running? Mine flicks at 96%? Is that because it's an electric signal, and not a magnet?

Now to my problem. The sensor must be working, as the display show the rpm climb as predicted on startup and reaches a figure pretty close to the calculated maximum headspeed (factoring in their is no load on the motor). But it does this when I am running the governor (the "gov on" symbol appears). It doesn't matter if I choose 1400 or 1800rpm in the correct flight mode. In the operation response in the Governor Expert menu, I've chosen "response silent".

Also when running in gov mode, if I setup a normal throttle profile and turn gov off (in both CGY750 and 8FG), the throttle doesn't act in a linear way, it gets faster at each end of the travel Before trying to setup the cgy750 governor, my throttle worked properly, and I haven't reversed channels or switched motor wires.

Can someone create a setup guide for brushless motors?

[knightofcarnage]

Did you upgrade for version 1.31. Support is built in.

[Steve Evans]

You generally won't rely on the CGY750 to provide soft start. Most ESCs allow you to set startup behaviour and subsequent response separately. I generally spool up, taking advantage of soft start, until near the desired headspeed, and then switch to idle1/2 to enable the gov with desired headspeed. The StartupDly setting in the CGY750 provides some control over how quickly the gov with change the headspeed when acquiring lock. The higher the number the slower the CGY750 will respond. Note though, that if you set this too high, the gov will hunt and never lock. I generally use this at the minimum value.

Below is a plot of the gov being enabled with a startup delay of 2. The trace shows 1000 samples at 7ms per interval.


Below is a plot of the gov being enabled with a startup delay of 8. The trace again shows 1000 samples at 7ms per interval. Note how much more slowly the ESC output from the CGY750 changes.


I should point out that the above relates to experiments with version 1.2. 1.3 may be a different animal.

Steve

[Mixmaster Pilot]

Okay, but now how do I get the RPM I request on the CGY750 or TX? Or does none of those settings actually govern? They just give the sensor an idea of the headspeed I am running? So the only way to affect governor headspeed is by the TH curves?

Originally Posted by nightofcarnage

Did you upgrade for version 1.31. Support is built in.

1.3 at the moment, it's identical in programming support as far as I know.

[360Wings]

The rpm sensor will show 95-96% and switch between 0% and 95% as the motor rotates..
This is normal.

Make sure you set the idle and max throttle positions correctly, along with the % throttle the gov. will turn on.. I have mine set on 30%. My initial setup the gov. didnt turn on due to the gov, throttle switch being set to 60%...

The headspeed is controlled in the Tx using the Gov. menu. You can use the % mode or the rpm display mode.. I havent been able to get the rpm display mode to match the actual headspeed.. So i switch to the % mode and a rpm tach, along with the CGY750 display to setup the gov. head speed for each flight mode..

It appears the CGY750 has some sort of limitation on the max. h/s for overhead. Using either the Rpm mode or % mode the H/s tops out at 2100.. The gearing allows for much higher h/s and was previously running 2150 and 2200 with vbar gov..

So far the gov. seem fine.. No complaints, except for the rpms in the tx not matching.. Its kind of strange as they are Futaba products (Accept for the sensor - which is digital so it should be a bit deal).

[Mixmaster Pilot]

Originally Posted by 360Wings

So far the gov. seem fine.. No complaints, except for the rpms in the tx not matching.. Its kind of strange as they are Futaba products (Accept for the sensor - which is digital so it should be a bit deal).

Yeah I noticed that as well. Say the rpm is 1600 in the TX and you start dialing the rpm down, the CGY750 rpm starts off much lower (around 1200 for me I think) and while the number change correlates (goes up and down as you change the TX setting), it never matches?

[360Wings]

Originally Posted by Mixmaster Pilot

Yeah I noticed that as well. Say the rpm is 1600 in the TX and you start dialing the rpm down, the CGY750 rpm starts off much lower (around 1200 for me I think) and while the number change correlates (goes up and down as you change the TX setting), it never matches?

I played around with the endpoints to see if i could get it in sync. but it doesnt really work..

Rpm mode (1000-2500)

Normal - 64.5% , 1790rpm tx reading = ~1850 rpm (CGY750 readout , confirmed with tac)
UD1 = 91.5% , 2330rpm "" = ~2030rpm ""
UD2 = 108%, 2660rpm "" = ~2100rpm ""

I havent tried the 1000-3500 that might work a bit better?

[Mixmaster Pilot]

Yeah as you say, these two units where made for each other, so why won't they match up? Dr Ben?

[Steve Evans]

Use the +/- data buttons on the CGY750 to make the set speed match the Tx. Do this for a range of set speeds on the Tx (1500, 2000, 2500) and they will then match.

Steve

[360Wings]

Originally Posted by Steve Evans

Use the +/- data buttons on the CGY750 to make the set speed match the Tx. Do this for a range of set speeds on the Tx (1500, 2000, 2500) and they will then match.

Steve

Ahh, ok.. Ill give that a try tomorrow when im at the field..

Edit: Couldnt wait until tomorrow so i tested it on the bench.. It works.. We were just missing that calibration step.. Now, its pretty much spot on i.e rpm in tx = tac'd rpm..

[Mixmaster Pilot]

Originally Posted by 360Wings

Ahh, ok.. Ill give that a try tomorrow when im at the field..

Edit: Couldnt wait until tomorrow so i tested it on the bench.. It works.. We were just missing that calibration step.. Now, its pretty much spot on i.e rpm in tx = tac'd rpm..

Good too know, see we need some more info Futaba

[504Rone]

Is the gov performance on par with v bar?

[360Wings]

I was far from impressed with the gov. performance today.. My first flights with the CGY750 left me extremely happy with the tail( best tail performance iv come across), Piro are flat (better than vbar) and very stable in a hover. Gov. performance dreadful. Any pitchy move e.g. pitch pumps, tic tocs, even just a loop, it was able to keep up cause the heli to be sluggish and powerless.

Packed up and went home ready to put the vbar back on.. I checked the v1.30 updated documentation and found a setting that is the likely cause of my poor gov. experience, Response. I was running it on "Middle" but after reading the manual properly found it should be set to "Silent" if using a phase sensor..

So im back to the field tomorrow to see if this brings the gov. to life.. If it doesnt ill be forced to use the CC gov. Based on current experiences has 100% better gov. than the 750.

Ill report back tomorrow with test flight results with the "Silent" setting.. FIngers crossed.

[Mixmaster Pilot]

Have you made sure the ESC is set on it's most aggressive setting, eg. plane fast?

I'm not sure I'm going to use this as my governor, I really don't like that the CGY750 doesn't have a soft start, and my ESC doesn't have an external gov feature.

[RC Mike]

Is the CGY governor as good as the CC ESC internal governor? I’m talking about the latest CC 4.02 governor as it’s much better than the V3.xx governor.

[360Wings]

Had 5 flights his morning and with the gov. Mode set to "silent" it works very well.

I still need to tweak some settings for cyclic and tail to get them where I like but so far so good.

It's been ages since I flew with the cc 4.02 gov. Both are good, but I would need to do more flights with both the cc and 750 gov. To do a proper comparison.

Hopefully in a few more flights I will have by settings locked. With the gov. Sorted i can work non the rest of the settings.




Sent from my iPad using Tapatalk HD

[smittylube]

Originally Posted by 360Wings

.

Packed up and went home ready to put the vbar back on.. I checked the v1.30 updated documentation and found a setting that is the likely cause of my poor gov. experience, Response. I was running it on "Middle" but after reading the manual properly found it should be set to "Silent" if using a phase sensor..



Ill report back tomorrow with test flight results with the "Silent" setting.. FIngers crossed.

This is stated as well in the current 2.0 info from Futaba for best electric gov performance, but I don't see the response in the basic or advanced menu tree. Has this been removed in 2.0?

[Dr.Ben]

Response time is now tied to motor pole count range and set automatically. The silent mode stuff should have been removed from the current manual.

Ben Minor

[smittylube]

Thanks for clarifying that Ben.

Sorry- off topic, The current manual states trim flight, yet searching for drift some suggest the trim only applies to the tail. I had a slight left roll or drift that I made a slight mechanical adjustment to hopefully help, but it still rolled left at times and then right at times..

Does that indicate I could/should use more gain? Or does the trim also adjust for roll?

[Dr.Ben]

Steve,

There is no rate mode or trim flight in 3D mode in 2.0. If you have a drift, double check the swash is indeed level or certainly has no left tilt. Particularly in hover, head gain has a BIG effect on the presence of drift. With higher settings, the gyro holds extremely well in hover.

Ben Minor