Gov issues with neo/tribunus 200A (fixed!)

I'm having some issues with the vbar gov and the scorpion tribunus 200A. With the vbar gov enabled, headspeed surges badly causing a bad tail wag in a hover. If I set the ESC to use the internal gov instead, it holds a perfectly flat headspeed. I'd prefer to use the vbar gov, if possible, but I don't know what to change to fix this. I've tried setting gov gain and gov I gain to 0 with no differences that I could tell.

Attached is the headspeed graph from testing (albeit with blades off). The first spoolup I'm gradually increasing the basic throttle setting, second spoolup is the scorpion gov, and the third and fourth are back on the vbar gov.

There's no errors in the vbar log.

ESC has firmware version 43, neo is brand new and up to date. Motor is a Xnova 50xx-450kv, running 14s.

Any ideas on things I can try?



Edited 1 time(s). Last edit at 04/23/2017 07:04PM by smwht.

How are the VGov settings? - Please post screenshots of Gov Setup and Gov experts (all banks) and the gains.

regards (EN) / Gruss (DE)

Rainer Vetter

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Here are the settings. I also updated to the v44 firmware for the ESC just now, no changes. Behavior is approximately the same in bank 1/2/3.

In case it helps, I looked at the PWM output on the vbar UI log, and it looks to stay at approximately the same PWM after the first few seconds, and it fluctuates only +/- 1 on the graph. I'm gonna try bypassing the power bus (protos max power bus - PCB thingy) just in case.

Edit: no different with a direct throttle cable.



Edited 1 time(s). Last edit at 03/23/2017 02:12AM by smwht.

Can you describe how much the tail moves and how deep the surges are. I found a similar effect on my one, but not bad, just a little. It appears on low PWM and not at higher PWMs. Here is probably some room for improovements.

so long ... Uli
http://www.vstabi.de

https://youtu.be/V7aiXZ-Ppf8 quick video showing behavior in a hover, attached is the UI log for this flight.

First I hover with the scorpion gov - headspeed is about 1100, I've done no tuning so far, this was mostly for my benefit because I've only tested with blades off and I wanted to make sure it works with blades on before the nice weather this weekend. Then I switch to the vbar gov and set bank 1 and bank 2 to 1400rpm - bank1 has 0 gains, bank2 has the default 30 gain. I took off in bank1, then switched to bank2 after a few seconds.

Apologies for the lighting/quality on the video, hopefully it's enough to see.

Hi,

why do you got "0" values in your bank 1?

Do you got tail wag in all RPM´s?
What helicopter is it and what are the RPM´s in your Bank 1/2/3 1400, 1600 and 1800?
Maybe you can take a short video if you can´t solve your issue after the steps below:

Please try to set up govenor as an "external govenor" and then switch back to "VBar electric govenor" in your Vbar control and also do that with the internal setting of the Tribunus (enable internal govenor of the Tribunus and then switch back to Vbar Govenor mode) and try again.

Please keep us posted ;-)

HeliALEX Wrote:
-------------------------------------------------------
> Hi,
>
> why do you got "0" values in your bank 1?
Testing to see if the wag was gov gain related

> Do you got tail wag in all RPM´s?
yes

> What helicopter is it and what are the RPM´s in
> your Bank 1/2/3 1400, 1600 and 1800?
Protos max v2 800 stretch. Currently 1400/1600/1800, planned headspeeds are anywhere from 1100 or so to 2000. Have to see where it feels right on the low end, just got it put together so I haven't tuned anything yet.

> Maybe you can take a short video if you can´t
> solve your issue after the steps below:
>
> Please try to set up govenor as an "external
> govenor" and then switch back to "VBar electric
> govenor" in your Vbar control and also do that
> with the internal setting of the Tribunus (enable
> internal govenor of the Tribunus and then switch
> back to Vbar Govenor mode) and try again.
>
> Please keep us posted ;-)
I've swapped back and forth between gov modes a few times, see also the video in the previous post.

Watched the video and the low head speed is your trouble, the thing has only just enough rotation to take off IMO.

Ramp the head speed up and the problem will disappear.

I get the same as you in the video. I classify it as "little". Its visible on low PWMs in hover only. But still it can be improved i think. Problem is imo the too strong braking on little input changes. Ill contact Scorpion on this, lets see what we can do.

so long ... Uli
http://www.vstabi.de

I tried 2000 rpm on vbar gov, tail wag isn't much different. Gearing puts me closer to 2100-2200 rpm max governed HS, but 2000 should be pretty reasonable PWM-wise I'd expect. 2200 rpm on 800mm blades would be... exciting, I think.

I'm just gonna use the scorpion gov for now, seems ok in a hover at least in the headspeed range I'm planning to run.



Edited 1 time(s). Last edit at 03/24/2017 09:23PM by smwht.

I updated to the v48 scorpion firmware, problem is fixed. Tail is solid at 1400 rpm on the vbar gov now.

Hello,

I have the same problem as you described in your post. I have latest firmware on Tribunus but still not working as it should in Vbar gov. Did you change something else as well to get it working?

Thanks