TT DII VSGV RV-7 settings?

I've got a TT DII VSGV linked to my Garmin 430W and GRT HX units in my RV-7 and I am having problems with stability in the cruise when on Autopilot....essentially relates to hunting up and down through up to +50ft and -50ft of my set altitude (it is not a trim issue)

Can anyone with an RV-7 and a TT DII VSGV help me by sending me their settings so I can compare them to mine?

Thanks in advance.

Regards

Jon

make sure you have the most recent software

I don't remember the version numbers, but I had this same problem with the same setup you have until I upgraded to the most recent version.

From GRT's list of fixes for the software that came out in August 2010:

"Add Pitch Activity multiplier setting and halve internal multiplier to fix pitch oscillations"

DBone said:

I don't remember the version numbers, but I had this same problem with the same setup you have until I upgraded to the most recent version.

From GRT's list of fixes for the software that came out in August 2010:

"Add Pitch Activity multiplier setting and halve internal multiplier to fix pitch oscillations"

Click to expand...

I believe this is the issue with your system if you have not upgraded to the newest version 3 for the HX and .34 for HS.
One good way to test is to set your TT in heading mode and not coupled to the GRT. If it still hunts, then there is a setting issue with your TT, otherwise it is an issue with GRT and most likely the version. Also, with the older version, if you make sure the plane is trimed, it should not hunt for the altitude any more.

Does it hunt when you put TT into ALT HOLD (instead of GPSV). If yes, then this is not related to GRT at all, and would most likely be solved by bumping up Static Lag...

I'd try with static lag set to 1 or 2... it should help..

Thanks all for the prompt feedback

It hunts both with and without the HX operating the autopilot - seems worse when the GRT is driving it though.

I'll upgrade to the latest HX and AHRS software and will adjust the TT setting numbers and give it another try.

Will report back.

If anyone else reads this and has their TT setting numbers handy - would appreciate if you could post them.

Cheers

Jon

TT almost the same ..... but what about the GRT gains?

Flying a DII VSVG and 430W and H1 in a 7a so they should be pretty close. I have the lateral and vertical activity on the TT set to 4, roll rate high, everything else as indicated in the manual. The TT flys godd by itself but not so good when on the H1.

There are about 8 different gain settings on the GRT Horizon. They are all set at 1 to start with and you double the setting for each one. Roll, Pitch, VOR, Heading, Cross Track, etc. So the settings go from 1 to 2 to 4 to 8 to 16.

I am at the point now where on my last flight, I set all the gains to 2, then the Roll and Heading gains to 4. I think that helped but haven't really got it checked for sure.

I would REALLY appreciate it if anyone could list thier gain settings in the GRT to go along with the TT settings.

All help appreciated.

Bill S
7a flying 32 hours now and on the way to SnF

me too

Since upgrading the TT Digi II VSGV to 2.44 two weeks ago (from 2.18) the AP hunts vertically quite a bit and really has trouble following the ILS. It never did that before, it was rock solid. I have the latest EFIS sw versions.

Looking for GRT settings from anyone that has this working properly with a TT. I called GRT but everyone is at Sun-n-Fun. I have been slowly making changes to the settings and while it has gotten better it's far from ideal and I wouldn't trust it to shoot a real ILS approach.

walter said:

Since upgrading the TT Digi II VSGV to 2.44 two weeks ago (from 2.18) the AP hunts vertically quite a bit and really has trouble following the ILS. It never did that before, it was rock solid. I have the latest EFIS sw versions.

Click to expand...

I have heard about the newer version of TT to have some issues and have not upgraded mainly for that reason. It is too bad that they can not be upgraded/downgraded on the plane at home. I would think if it was me, I would be sending it back to for a restore unless there was some other fixes with this upgrade.

Update

I put Altons numbers into my TT DII VSGV on the weekend and gave it another try (feeding from the 430W rather than the GRT HX units). A number of my settings were different and the vertical stability has definitely improved but i can still fly it better by hand.

I would really appreciate it if someone could provide their settings for the GRT HX units combined with the TT DII VSGV if it's not too much trouble?

Thanks again in advance.

Cheers

Jon

Settings

Here are mine, RV7 W/ 430W, TTvsgv, dual screen (1WS, 1HS) and it is real stable but don't have the GRT HX but you can try it

Lat activity=3
Lat Torque=10
Bank angle=med
GPSS Gain=16
Vertical Activity=0
Vertical Torque=12
Static lag=0
Microactivity=0

In EFIS General setup all AP settings are set to 1.00 except:
Altitude hold= .25
Vertical speed gain= .70
Glide slope gain= .25
I have the latest EFIS,Arinc,TTvsgv SW

A vertical activity of 4-5 in any of the two-seat RVs is actually a little high. It should be most stable around 1-2.

Can you give me a better description of what it's doing with the autopilot on altitude hold mode?

The newest software frond GRT has resolved the issue for most people.

I got to check my settings today and they are as follow

Lat activity=3
Lat Torque=12
Bank angle=high
GPSS Gain=16
Vertical Activity=0
Vertical Torque=12
Static lag=0
Microactivity=1

With GRT EIFS I get hardly any vertical hunt, maybe 5-10' at most but for lateral activity watching my stick or wing tips, I see a bit of rocking, ever so slightly.