SK720BE Governor

[gokl]

Hi,

i wanna use the governor of my SK720BE with my Hobbywing Platinum v3 50A. I have some questions about this:

1. Do i have to use the soft spool up from my ESC or does the SK720 governor support soft spoolup?
2. Whats the unit of the Low Ramp and High Ramp values? Whats will happen if i lower or increase the value there? (I know the settings are for how fast the SK switches to the new RPM)
3. Does the SK governor support auto rotation bailout? If so, how does it work?

Thanks
gokl

[sctholson]

There was a discussion in another forum about the platinum v3 and I believe that those guys determined that they needed to run the esc in heli mode gov off. I have v2 and there is only airplane mode and gov on, so I can't really help beyond that comment.
The low ramp and high ramp settings have pop up boxes that describe them. I have mine set at 70 and 70, some use 80 and 80. You'll have to try to raise them and lower them to see how your set up reacts
No auto bailout that I know of, someone else can correct me if I"m wrong.

[Digger1973]

The sk gov does have auto vail out. Set th to approx -16. Search for it for more info on auto bailout

[Inkslinginmofo77]

Your initial spool up is started by the ESC then is handed off to the sk unit to bring to head speed. High and low ramps are kind of a slope or "ramp" if u will, that determinines when the initial spool up is handed off to sk gov amd how fast it reaches head speed etc. look at it like this
120 High ramp

100

80. Low ramp

It's an adjustable gove slope u can configure to take the spool up hand off and adjust to your liking. Check out attachment to get a visual perspective on ramp and spool up process

[gokl]

Thank for the answers so far. But i still dont unterstand the connection between time and the ramp values. Somehow the values are related to how fast the desired RPM is reached. Is this correct? Is there a formula or something?

[Inkslinginmofo77]

Originally Posted by georgi UK


The gov ramps consist of

Low, this controls the slow spool rate which can be reduced to 10% for a near turbine type start up, as the RPMs increase the gov takes over with authority to the set RPMs. It's max rate is 400%. So this only affects the first part of the throttle, it has no bearing on the second part. The low ramp isn't used by the bailout so we set this to our preferences.

High, this controls the second half of the throttle and how quickly the gov reaches its target RPMs, so we can see, initially the esc arms with its start setting, the SK gov takes over at its low ramp setting, this feeds forwards until the high ramp setting gets its cue to increase to the target. The gov then does its work to hold it there.

Overdrive, the actual value here is in RPMs, if the head speeds start bogging or decay badly with hard moves, the gov may need to apply higher RPMs than the target to do its work more effectively, this is more for nitro's, electrics are usually overpowered missiles!!

For the auto bailout the esc needs a normal start setting, a low value setting for the low ramp spool, then a high setting in the high ramp spool. TH uses around minus 15% in it's setting.

I did do a pictorial diagram some time ago for this, outdated now I guess!!

[sctholson]

Originally Posted by Inkslinginmofo77

For the auto bailout the esc needs a normal start setting, a low value setting for the low ramp spool, then a high setting in the high ramp spool. TH uses around minus 15% in it's setting.

I'd appreciate more info on how this works. I did as suggested (search google for auto bailout) and didn't find anything remotely related to autorotation bailout and setting throttle position. I also don't see anything like it in the 720black manual version 3.99

Any links or broadening of the above would be appreciated.

[georgi UK]

=] I use the V3 running default SK ramps, this works well and there should be no need to change them. low ramp affects <50% spool speed, high ramp 50%> to target rpm's.

this esc takes 11 secs to get to full rpm's, has a nice HW slow start, outside of Elf mode and gov store it enters into a restart slow spool which is useless for AR bail-outs, I have yet to try airplane mode, some v-bar users do.

[gokl]

Id did some flying with the SK governor and the ESC in 'heli governor off' mode but after tuning governor gain and tail gain i still have little nervous tail. I believe its governor related, but im not sure.
Its flyable, but when i hover the tail does little movements now and then. When i flew without governor i didnt have this kind of problem.
Is it a matter of fine tuning the gains or could it be related to something different?

[Inkslinginmofo77]

Can u describe the tail movements a little better and what settings u have enabled?

[gokl]

Its little left-right corrections made by the tail. I had them very strong after initially switching to the SK governor but this was due to a too high governor gain. Im now using around 15 and started with 50.
Ill take a closer look at the movements tomorrow when ill be flying again.

[Inkslinginmofo77]

Usually gov gain affects dropout and recover headspeed and maintaining. Which could make the tail kick. Try hovering at a level speed and watch the tail. If it does it then it's more a tail gain issue. However if it does it only with harder flight then it could be a matter of adjusting mix fields in tail setup. But from how it sounds it may either be tail gain or possibly a sticky linkage. Unsnap the tail pitch linkage and double check u have zero resistance and binding. Just to make sure. Then adjust settings according to flight behavior. I had the same issue and was always used to using around 30 gain on tail so never strayed far and could never figure it out. Finally out of curiosity I jacked up my tail gain to 40 and it fixed it. Still corrected but not noticeable. Only like an inch travel but really good. Also maybe try a little higher head speed as the update may make the gov behave differently for improvements. But fly it and provide a good description of behavior and flight style used.

[omerco]

Originally Posted by gokl

Id did some flying with the SK governor and the ESC in 'heli governor off' mode but after tuning governor gain and tail gain i still have little nervous tail. I believe its governor related, but im not sure.
Its flyable, but when i hover the tail does little movements now and then. When i flew without governor i didnt have this kind of problem.
Is it a matter of fine tuning the gains or could it be related to something different?

This is normal high governor gain description.

but your governor gain is very low.
25-35 is normal range so it could be you are over-geared.

what are your:
main gear tooth count.
pinion.
motor KV
cell count for battery.
Desired RPM.