dlrk Posted June 7, 2013 Share Posted June 7, 2013 When I try to use SAS/ASAS on a spaceplane(or rocket with control surfaces), the craft bounces and shakes in a semi-controlled manner. I'm using FAR. Any tips? Link to comment Share on other sites More sharing options...
Sᴄɪɴᴛɪʟʟᴀᴛᴏʀ Posted June 7, 2013 Share Posted June 7, 2013 Standard SAS has no effect as an automated steering device, it merely gives you more torque to control your ship. The ASAS always over-compensates and it uses all of the controls available to it to keep the craft on course. The nosecone ASAS is much more stable when used for flying, have you tried using that. Link to comment Share on other sites More sharing options...
Cranium Posted June 7, 2013 Share Posted June 7, 2013 When using control, SAS only has stability to stop roll. ASAS uses all control surfaces, and any available RCS, gimbals, and even an SAS to control your craft, and it will do its best to keep you to your original heading no matter what. The nosecone mounted Avionics Package does all that the ASAS does, but it will not fight you to keep control of the plane. This makes the AvPa much better for spaceplanes, as it allows you to still control your plane, but also will try to keep a straight heading, without vibrating itself to death trying to fight you. Link to comment Share on other sites More sharing options...
Scoundrel Posted June 7, 2013 Share Posted June 7, 2013 What he's talking about is porpoising. What's happening is that your control surfaces and any thrust vectoring engines are all on the same longitudinal line. Move your tail or canard surfaces a bit up or down - I mean literally up or down, not forward or back - from the control surfaces on your wing (if any) and any thrust vectoring engines. This will cause your plane to be more stable as the game/plug-in recognizes that your control surfaces are at different vertical positions and they'll work to cancel any overcorrections out. The further separated they are vertically, the less porpoising you will have. Link to comment Share on other sites More sharing options...
dlrk Posted June 7, 2013 Author Share Posted June 7, 2013 I am using the nosecone avionics. I'll try moving the control surfaces vertically, but it doesn't look like porpoising so much as rapid overcorrection. Link to comment Share on other sites More sharing options...
Scoundrel Posted June 7, 2013 Share Posted June 7, 2013 (edited) Rapid overcorrection is pretty much the only cause of porpoising in the game. It's called that because the aircraft behaves like a porpoise - diving into the water, then climbing into the air, and then diving back into the water. Horizontal (yaw) porpoising is also encountered, typically through too much rudder and its subsequent overcorrection, but in some cases when an aircraft porpoises, it tends to roll, which causes the vertical control surfaces to get involved to keep it from rolling further. It's complicated and there's more qualified people than me who could discuss the nuances on the various avionics packages available in KSP.A good example to see if your control surfaces are set up properly is to get your craft airborne and then do a barrel roll. If you lose control or the plane feels like it's about to lose control, then your control surfaces are set up improperly. Vertical separation is usually the solution. On the other hand, it is also possible you have too much control surface for the weight/lift of your craft, but without a pic I can't say for sure.Edit: AAAAnd like an idiot I somehow missed the part about the control surfaces on the rocket. Yeah, you need to turn off the gimballing on the engines while your control surfaces are in action. That will help keep your rocket steady, though if the rocket is too long, the natural structural wobble will cause the rocket to oscillate as the engine/control surfaces attempt to correct for the wobbling up top as well. It gets ugly really fast. Edited June 7, 2013 by Scoundrel I'm a moron Link to comment Share on other sites More sharing options...
franciscoexmachina Posted November 25, 2014 Share Posted November 25, 2014 I have also noticed a big difference between the effects of FAR in previous version (specifically .23 and .24) and the one released for .25.I'm not sure how impact the wings mass tweakable has, but the Control "Ctrl Dflct" tweakable is changing the impact of FAR considerably. Someone please correct me if I am wrong, but I have reinstalled the .25 game, no mods, just FAR to test this: with FAR, any plane, even the ones that come with FAR, will have you pitching up and down (wobbling up and down) if SAS is enabled, as long as the Ctrl Dflct is left on its default parameter. You can avoid this by reducing Ctrl Dflct to a lower number or disabling SAS altogether (which makes keyboard flying quite hard, at least for me).If you check say, Scott Manley's Interstellar, recent episodes will show him piloting his new space place to Minmus and Eve, and you can see how SAS is always enabled. This is how I used to fly these space planes, but since update .25 (and corresponding FAR versions), I have simply gave up on using space planes, because I don't want to fly them without FAR. I had assumed this was a bug, but no one seems to be mentioning it anywhere, so I guess this is just about new features, not bugs, and I will need to either give up on space planes for good or learn how to fly them without SAS.I would really love to be proven wrong, and someone tell me planes still fly exactly like .23.5 or .24 with FAR, but in my own environment, that does not seem to be the case.Anyway, if anyone has a similar impression, take note that decreasing Ctrl Dflct will give you back at least some of the stability you were used to in previous version. Link to comment Share on other sites More sharing options...
Specialist290 Posted November 25, 2014 Share Posted November 25, 2014 Whoa, this is a blast from the past... I think the thread OP might have moved on to other issues by now.That being said, thread closed. Have a nice day Link to comment Share on other sites More sharing options...
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