Protos 430mm vs 470mm VBar settings

[whisperdancer]

I'm still dialing my Protos Stretch settings, as I'm struggling with the tail and main rotor. It's still a little far from being as stable and precise as the 430mm heli.

After assembly, I did a new setup and copied all the parameters (not setup) of the "small Protos".
First impressions were a tail that had wag and a bobbing on the main rotor when giving elevator. The tail wagged badly at hover, and all the heli seemed to twitch.
This with the same settings that made the other heli so perfect. Same motor, same ESC, same cyclic and tail servos.

After some packs feeling too unconfortable, I started playing with the tail settings. I was getting nowhere, until I dropped the P-gain and the I-gain, raised the acceleration a bit, and boosted the overall tail gyro gain (I think it's on the Logo 600 value).
It's not perfect, but not bad either.

As for the main rotor, I had to bump the gain to 105 to get rid of some of the bounce.
Still, it doesn't track like it's on rails as the 430mm bladed does.
Before going up on the main rotor gain, giving backwards elevator gave a bouncy feeling, much like the T-Rex 500 I once had, as if the heli weighted too much or had a low HS. It still does that at lower HS (2400). The normal HS is around 2700-2800rpm.
Going in a straight line FF, I could see the heli bobbing on the main rotor (back and forward) and the problem was worse in slow banked turns. I'm sure the head is fine and correctly assembled, and the dampers are in good shape as they don't have many flights and seemed perfect when converting to FBL.
The servos (all the 3) have a little play (nothing alaming), but it flew perfectly with the flybar, with aileron stops on a dime just like the other Protos. I bragged about this to all my fellow flying friends.

Only differences between helis are, besides the stretch kit, the CF tailblades on the normal Protos (I could balance them finaly ) and the swash (stretch has the old swash that wobbles just a little bit - I don't think this is the cause of any problem). I'm still waiting on the new tail hub, but the normal protos has no vibrations, and the stretch has around 500-600 in midflight(measured with bluetooth).
Balls are on the recommended servo hole on the main rotor and on the 13.5mm hole on the tail.


How is it possible that two similar helis behave so different and need very distinct values to get the same result?

I send you the files (tail rotor gain is connected to the AUX on the radio, so the value is not real in the stretch). Log is from the stretch and the high vibrations are from the small autorotations on hard pavement.

EDIT: moved to VBar forum