Helijive mode 8

[DannyvG]

Are many people using mode 8 of the helijive and how is it working?
How reliable and safe is it with vbar 5.3 and helijive version 13?
Any problems when using it with a non-kontronik motor?
Any tips on how to set it up?

Is it correct that in mode8 there is a 6second softstart in the helijive, or is there no softstart at all in the esc?
I am wondering if it would also work with the MSH Brain, but there it seems to work best to have no softstart in the esc but perhaps if it is only 6 seconds with the HJ then it might work.

[dl7uae]

The external gov (vbar) starts a throttle ramp.

At 12% throttle the JIVE starts the spoolup.

The ext gov should give the JIVE at least two seconds for that, means stop his ramp-up during that time. Should..

The potential problem is that the commanded rpm (throttle->pwm->rpm-by-kv-and-voltage) is not synchronized in any way between ESC and gov. No synchronization between rpm (pwm) and external throttle value. Especially the mentioned throttle ramp should be well coordinated to the status of spoolup from standstill.
So most times there will be a little hiccup at the transfer point.

That's not very good, chance for a commutation failure.

Now guess what the answer is on your motor question.

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In a car with a non-synchronized gearbox can certainly engage the next gear without using the clutch. You have to master only...

[DannyvG]

Originally Posted by dl7uae

The ext gov should give the JIVE at least two seconds for that, means stop his ramp-up during that time. Should..

I guess you say should because I dont see any flat part in the yellow curve and I presume that curve represents the vbar spoolup

Why is the Jive so sensitive to jumps in throttle input? Because for example yge has no problem with this. Would it help to set the jive to fixed timing?

The following is pointless because kontronik will likely never change it...
And I would think it would have been a lot better if the jive used a properly calibrated zero-throttle (not start at 12%) and had a very short softstart (actually non-existent like airplane mode normally has? ) then it would simply follow the vbar rampup from the start and there would be no jumping or handing over.

[dl7uae]

Why is the Jive so sensitive to jumps in throttle input?

It isn't.

Please distinguish two states:
- Spoolup from standstill. That is the sole job of the ESC.
- Commutation running.

Between both states the agreement is, to wait! Ramp runs or jumps to 12% of throttle, spoolup from standstill starts. Therefore we have another, most important agreement: About the throttle pulse length, and so, who is who so to speak. No teach-in of the pulse length understanding in mode 8.

Then the external gov have to wait! Have to wait that commutation runs. Here are our 2+ seconds. It's up to the ext gov not to provoke a problem.

After that, with running commutation, you can do with throttle what you want.

[DannyvG]

thanks for the info

anyone who is using mode 8 with the vbar? how do you like it?

[Magneto]

Mode 8 is designed to be used with the VBar and Pyro motor only ,The default soft spoolup speed is not to be changed as it is necessary for the handoff of the govenor to the VBar.The performance of the other Heli modes 4,5,6 are better than using a external govenor mode 8.

[OICU812]

Originally Posted by Magneto

Mode 8 is designed to be used with the VBar and Pyro motor only ,The default soft spoolup speed is not to be changed as it is necessary for the handoff of the govenor to the VBar.The performance of the other Heli modes 4,5,6 are better than using a external govenor mode 8.

I respectfully disagree with this statement. Even though you can tune the PID of the Jive via the program disc you still can not smoothly delay the "snap reaction" time as you can with external governor mode. I will not disagree that the Jives have one of the best standard governors there are, however the tuning is not only easier externally but also and easily seen improvement when dealing with high torque motors & high powered systems. The external feature which allows the FBL to control also takes into account the other active parameters as well ie: collective position/pitch etc, therefore more speaking to achieve a more accurate account of whats needed for rpm. IMO mode 8 is the best mode for better tail behaving in both quick collective changes and even seen in natural smooth transitions. Myself and a few other fellows discussed and demonstrated this very fact with Jan Burmeister (since departed K) ..Ircha 2011....Thus after that MODE 8 was created.

Come Ircha if all stars align and I'm there I will be glad to demonstrate the difference, its easily seen and noted in easy to replicate maneuvers. In order to have a perfect or close to behaving tail you need a governors "catch" to have some give/delay although minute it's important, if too aggressive and no cushion on this catch the tail is visibly trying to catch up to the governors reaction to load changes. Even the MKS X8 can not react quick enough to "disc load" only positioning.