Jazz governor RPM "target"

[MrMel]

It has been much discussions forth and back regarding the Jazz RPM being inconsistent, so I did some testing.

There is TWO parameters, I only thought it was one but that never explained some behaivors.

1. Voltage at connection.
2. Powercapability/voltageflux during spoolup.

Meaning, if you for sample like me have a "normal curve" its VERY important to goto ZERO pitch immediatly else there will be load on the heli during spoolup and RPM will change, if you apply different load on different startup, you get very inconsistent RPM.

Of course a different quality battery will affect it greatly too regardless.


So, Flip the switch startup with zero pitch is my best bet to get fairly consistent RPM (if you dont use APM on PowerJazz and start with spooling upp to 100% which is the most accurate of course)


- Fredrik

[JKos]

Good info Fredrik.

I just wish Kontronik would change their method. I doubt they ever will, though.

- John

[MrMel]

I actually think they shouldnt, I suspect this is the "cause" why the Kontronik governor works as good as it does.

If it kept the same range, with a inferior battery, you would instead get bogging, Ive tested a brand new 25C battery vs a really old on the brink of death 20C battery and RPM difference was huge, however, the bogging wasnt because the lower RPM on the crappy battery.

[JKos]

Fredrik,
I say give the user that choice; not force it on them. It is quite annoying that you can't get consistent headspeeds even with the same battery pack.

Sorry, just a sore point for me with Kontronik ESCs. I think they are THE BEST period, but not on this topic.

- John

[MrMel]

But they could do a "mode #10" for those that wants it :)


One thing though, if you get different RPM from the same battery (obs, not same session since its not full second time), then probably cause is that you have different load on spoolup, and that you can "take care of" by executing same routine on spoolup, I suffered from that now when I used "normal curve", better to spoolup at zero pitch everytime.

[Eyon]

with my 80-6-18 i would flip from hold to idle 2 at 0 pitch and head speed was perfect every time!

[OICU812]

Yea I always start in idle 2 at xero pitch, let HS stabalize then fly, works good. :wink:

[wrathofkhan]

revisiting an old topic, i understand (sort of) to start spooling at zero pitch.

my question is, how close to zero pitch do you have to be? when my pitch/throttle is in the center, how can i be sure that it is really zero degrees - or approximation is OK with Jazz? then, wouldn't duplication of HS be impossible (even with same battery pack)?

cheers, khan

[MrMel]

Aprox is Ok.

What you can do is to have zero with your bad batteries and pitch on with your good and the RPM is closer to each other.

But all this, remember one thing.
Its actually in a way a good thing to have lower RPM on a bad battery, if you run your bad battery as same RPM as your good battery, it will be drained faster.
Voltage is lower on the bad battery, amp draw will go up, runtime down.

[helicraze]

Yea I always start in idle 2 at xero pitch, let HS stabalize then fly, works good. :wink:
Same here!

[Mathias]

And here.

[767drvr]

Yea I always start in idle 2 at xero pitch, let HS stabalize then fly, works good. :wink:

What gov % is your Idle 2 ?

Marc