Tips for automating Starship-style actuating fins?

[GP_LeChuck]

I'm working on replicating Starship in RSS (using SMURFF rather than RO, so essentially just stock + expansion parts) and I'm having trouble getting much precision out of the control surfaces on descent. So far I've been using delta wings and wing connectors in conjunction with hinges to form the fins, and what I would really like is the fins to automatically adjust in conjunction with SAS to keep the orientation of the craft. I tried assigning the appropriate pairs of hinges to pitch/roll/yaw, but since axis groups don't work with SAS, I'm stuck making manual adjustments with WASD/QE. Maybe I need to just work on my piloting skills (virtually 0% of my play hours have been devoted to flying planes) and/or adjust some settings in the axis groups (where I can't say I have a super thorough understanding of all of the options, e.g. incremental vs. absolute control), but it seems like this manual input leads to a lot of overcorrection and the whole thing spiraling out of control. I've had more success with assigning each hinge to different action groups and just toggling the fins forward and back--i.e. if I notice the nose starting to pitch forward, I tuck the bottom two fins away and leave the top two out. This works pretty well for the majority of descent through the atmosphere, but once it gets thick enough (let's say around 50-60km when deorbiting), things start to get a little out of control. Toggling any one of the fins at that point tends to just make things worse, so I just say Jeb take the wheel and pray the tumbling flaming carrot of doom doesn't explode into a million pieces.

Again, the ideal solution for me would be to have the hinges make automatic, minute adjustments in the manner of RCS/SAS, but I'm not sure how to make that happen. What sort of suggestions do people have to make for a pretty, stable belly-flop rather than a whirling mess? Should I make my fins out of control surfaces like elevons instead of BG robotics? Do I need to be looking at aerodynamic design/COM issues? Should I just load down the ship with reaction wheels and pretend my fins are doing the work? Is there a chance my angle of attack is wrong (I've been holding Radial Out; maybe I need to shoot for like halfway between there and Prograde?). I've seen a couple Starship recreations on YouTube and their descents more or less seem to work properly, but I'm not entirely sure how they're controlling the fins--if there are any tutorials out there, I'm more than happy to just plagiarize their ideas!

[AHHans]

On 12/30/2019 at 3:23 AM, GP_LeChuck said:

but since axis groups don't work with SAS,

[Pet Peeve Warning: Start.] Feel free to up-vote issue #22946 on the bug-tracker. (Requires an account on said tracker.) [Pet Peeve Warning: End.]

[CBase]

On 12/31/2019 at 8:37 PM, AHHans said:

up-vote issue #22946 on the bug-tracker

Actually this could be solved even by an extension: Add ControlSurface as module to KAL, so it is recognised by SAS and connect one input direction to KAL control value. The big problem is you would need to feed back the torque your KAL provides in order for SAS to correctly use whatever you control. And here I stopped, because I had no idea how to calculate this. And this makes the mentioned issue as well a pretty big extension wish.

Edited January 2, 2020 by CBase