Update killed my craft. Need advice on how to stop going crazy

[fireblade274]

I feel like I need to learn to plane again, and its ridiculous:confused:

Note: KIS and KAS are installed, but not used at all on this craft. Idk if you need to have the mod to still access them

I've spent 48 hours re-doing my craft, an MSTO plane inparticular, that used to haul up a full jumbo tank efficiently, and more efficiently then a rocket. It was my favorite STO. I designed it to be able to haul up to 36 tons of cargo, and haul it back down, and be able to fly without any cargo, and come back down, after jettisoning 2 delta canards up front. It could also take off and get into orbit with no cargo, and still have the 2 delta canards on, which was necessary to be able to pick up to 36t from orbit and bring it back down without bringing anything back up. It just wont work anymore. Ive finally got it to do everything i want it to again, except I just cant seem to land with no cargo inside, even after jettisoning the 2 forward delta wings.

Original craft (that worked! Flawlessly! TOOK SO LONG):

36t cargo https://www.dropbox.com/s/dhbg75eqdby3e8h/LTP%203%20LR.craft?dl=0

0t cargo https://www.dropbox.com/s/4e4untik1rexxby/LTP%203.craft?dl=0

(both pairs of craft are basically the same, they just either have the jumbo already in cargo hold or not)

(attempted) Updated craft

36t Cargo https://www.dropbox.com/s/w7y3a34zxrn3i9v/LTP%204_1.craft?dl=0

0t Cargo https://www.dropbox.com/s/bhgmwxbcw64mvgn/LTP%204_1%20Empty.craft?dl=0

These work after many many many tweeks

(0t of cargo on return, this is my issue)---> https://www.dropbox.com/s/d7auhyjlh8a5rmr/LTP%204_1%20Empty%20test.craft?dl=0

Above is what the craft looks like when it spins out on final approach upon slowing down from the re entry, ill pull up just a tad and it will spin out. This is where i'm getting problems. Once i was able to recover, and then spin out again.

Here is a video of whats going on: http://plays.tv/video/56444b6b785e5bdba6

Is my COM too far back in my craft? I really have no idea how to fix it. Even making only one elevator pair in the back of my ships tail active to pitch still sends it tumbling, and my lift is decently behind my COM. The many elevators are needed for when the craft is full of cargo, it needs the pull up reaction to be adequate..

I got it back to where it can get to orbit with or without max cargo. But it still cant land with no cargo. Keep in mind what I need to change here, I will also need to change on the other version of the craft that carries the 36t cargo. Because that's the purpose of the ship, to be able to put largo cargo into LKO, take large cargo back down from LKO, and fly with no cargo. basically be super versatile and economic. They are both the same, and I wont settle till they can both be the same and do 2 different jobs! IM NOT CRAZY! I SWEAR! YOU DONT KNOW ME actually yes i am crazy ITS JUST THAT i EVENTAULY MADE IT WORK PREVIOUSLY AND IT DOESN'T WORK ANY MORE. iM going insane over this yes.

Edited November 13, 2015 by fireblade274

[jwbrase]

Dropbox wants me to create an account to download your files, which I don't want to do, so I can't view them, but I think the issue that the Whiplash got reworked to be a bit longer, which I think has moved its COM back a bit. This, in turn, moves the COM of your whole spacecraft back, which is leading to aerodynamic instability. One of my spaceplanes remains more or less stable aerodynamically, but now sits on its tail on the runway if I launch it with no cargo (the original design had some issues of this kind to begin with, so I lightened the load in some of the aft fuel tankage and put in extra tanks up front to weigh the front end down. I now have to shift even more fuel forward to get it to sit on the nose gear instead of the tail.

[Van Disaster]

That thing dropbox does is annoying, but you can usually just cancel the login request & carry on anyway.

[Moss]

Someone else on the forums has said something which I'm going to shamelessly paraphrase because I think it's quite valid. SQUAD needs to internalise the fact that this is not an early access game anymore. The updates they release need to stop breaking existing designs or changing the way people play too much. KSP is a finished game now. The new heating and drag mechanics seem like a real blister for everyone at the moment. I personally haven't played much for that very reason.

[TheXRuler]

Well it's a little hard to tell but that definetly looks like a CoM vs CoL issue. What might help us help you is posting some editor screenshots using [thread=35996]this nifty little plugin[/thread] basically it displays wet CoM vs. dry CoM. Absolutely essential when building airplanes (of course you could just drain fuel manually but why make things more complicated huh? Also, oncce you have verified that Com dCom are relatively close you might want to bring up the fuel displays for every tank so that you can make sure it drains fuel evenly. If it doesen't try [thread=25823]this wonderfull piece of coding goodness[/thread].

[Majorjim!]

Someone else on the forums has said something which I'm going to shamelessly paraphrase because I think it's quite valid. SQUAD needs to internalise the fact that this is not an early access game anymore. The updates they release need to stop breaking existing designs or changing the way people play too much. KSP is a finished game now. The new heating and drag mechanics seem like a real blister for everyone at the moment. I personally haven't played much for that very reason.

This!

It is unacceptable to change the game so much after release.

[KerikBalm]

Seems to me like what you need to do is move the engines forward, because the CoM will shift way way way back after decoupling a 36 ton payload.

I'm surprised that it worked in 1.04. I notice in your video, you pitched up very abruptly. I've had designs before that were a bit unstable, but active control was sufficient to keep it flying straight if you were "gentle", and didn't try to turn too fast... perhaps that is what is happening now?

You should design your payload bay so that the CoM is at the center of the payload bay.

Move all your aerospikes engine nacelles forward.

Consider getting rid of the aerospikes altogether, put your turboramjets where those were (including moving them forward)

You'll then go from 4 turboramjets to 6, which will improve your airbreathing regime, and allow the airbreathers to haul more stuff.

50% more airbreathing thrust

Then you'll also be able to get rid of the fuel lines, as the turboramjets won't need them (you can change the 1.25m LFO tanks for LF only tanks, or just manually transfer fuel from them to the core section in space when in orbit or nearly so) - less drag.

Then get rid of the mk3 to 2.5m adaptor, and put on a mk3 to 3.75m adaptor (it is much shorter, same fuel capacity), and stick a KR-2L on there -> it has thrust vectoring, a better TWR, and the same vacuum Isp (which is all that matters for a spaceplane, because you don't light rockets until the air is very thin anyway).

While it is heavier (9 tons vs 1x6 tons for the aerospikes), it will be closer to the cargobay this way.

>50% more rocket thrust.

Then add a LFO tank in front of the cargobay, which will shift CoM forward, so its closer to the center of the cargobay, as well as increase your total LFO by ~50%.

50% fuel increase

50% or greater thrust increase across the board

less CoM difference between with payload and without

Shift wings as needed for the new CoM.

Load more than 36 tons into the cargo bay (you can easily fit not just an orange tank, but also a Rockomax X200-8 Fuel Tank for +4.5 tons, Plus a lot of radially attached xenon or monoprop tanks)

Edited November 12, 2015 by KerikBalm

[fireblade274]

Thank you so much for your response's guys! I will test your ideas when i have a moment, i need to get back to my life after endlessly tweaking crafts to work again for 2 days. I really just wish this worked already. the CoL is decently behind the CoM, as in it is outside the yellow ball, but the CoM is quite behind in the plane with no cargo: in this instance the CoM is slightly behind the cargo hold and the CoL is even further back (but still far from being out the back)

[Van Disaster]

This!

It is unacceptable to change the game so much after release.

Well, it's not like practically all of us didn't bring this up both when they announced release *and* when they announced beta... ( like we've even got to beta yet anyway )

But they're not alone in doing this by any means.

[TheXRuler]

Well to be fair most games don't get anywhere near as much content after "release". I mean the work squad is doing is frankly amazing, heck they even want to update to the new version of unity and I have never heard of dev's actually upgrading to the next generation of an engine without calling it a new game and wanting full price for it again. Many games actually push out expandalones that contain fewer new features (eg Borderlands Pre Sequel and Saint's Row IV) so maybe cut them some slack. I know it's frustrating and I really do understand that it annoys people but nobody is forcing you to use the new upgrade and personally I am just happy they don't bring all this stuff out as DLC's.

Also fireblade, glad if we could help you

[Van Disaster]

Well they have to do U5 to get it on consoles. I don't suppose you remember the firestorm when Squad brought up DLC anyway I'm not going to bring all that stuff up in someone's problem thread.

One thing about having CoM so far aft is there's a lot of body in front of it to cause divergent stability problems, eg, yaw a bit & your body lift from all that pivoting fuselage in front of CoM is going to overpower any counter lift from behind CoM and you've got a natural yaw instability issue, and the same with pitch. Your stabs & control surfaces are best placed as far from CoM as you can ( conveniently the further they are the smaller they can be too ). Unfortunately plays.tv is not actually playing for me so I can't see the problem in detail

[Seajay]

Also worth checking that this isn't the body lift bug fixed in 1028 http://forum.kerbalspaceprogram.com/threads/139001-Silent-patch-for-KSP-1-0-5-published

[TheXRuler]

Well they have to do U5 to get it on consoles. I don't suppose you remember the firestorm when Squad brought up DLC anyway I'm not going to bring all that stuff up in someone's problem thread.

Mhhh no I must have missed that, or maybe I wasn't here yet

Also I second Van Disaster's point, that may well be an issue.

Edit: Of course if you were using FAR yoou would have those lovely simulation tools to help you figure it out

[Claw]

Yes, I would definitely check in the new version. Body lift was inadvertantly turned off in 1.0.5.1024. That's been fixed in 1.0.5.1028. That can have a huge impact on large designs.

Other than that, drag was increased a bit at higher altitudes, and (I think) degreased slightly at lower altitudes. At least for fast flying stuff. Although I can't imagine that would cause such a drastic effect as what you are indicating.

Cheers,

-Claw

[panzer1b]

Someone else on the forums has said something which I'm going to shamelessly paraphrase because I think it's quite valid. SQUAD needs to internalise the fact that this is not an early access game anymore. The updates they release need to stop breaking existing designs or changing the way people play too much. KSP is a finished game now. The new heating and drag mechanics seem like a real blister for everyone at the moment. I personally haven't played much for that very reason.

While i have nothing against changes, i do feel that this change does 2 things wrong, one, as you said, it ruins MANY craft that works prefectly fine before. Two, it (in my personal opinion) decreases the fun factor as the new aero ruins many SSTOs and spaceplanes due to both exponentially increased heating, and much higher and way more noticeable drag around the region of 20-40km, the critical spot for spaceplanes.

Ofc, like many, ill probably just adapt (i dont really like to edit physics.cfg as one, it makes my craft incompatible with others, and two, i kinda like to stick to stock in terms of settings, but yeah, im not a fan of 1.0.5's flight models at all now.

[fireblade274]

I finally did it! I was able to get it to land with no cargo by ejecting 4 of the 6 aerospikes and their fuel tanks before pulling up after reentry via decoupler. Quite ingenious if you ask me hehe, It meant that I had to do no alterations between the two designs, so they are still all the same ship at its core/last stage, they are just really versatile now . I still need the parachutes on them to be able to glide the jettisoned pieces down slowly enough to recover them, but it should be able to happen

I will say that after the update, although I'm in the process of fixing my ships still, progress is being made. But it is still really annoying. At the very least I wish they would up the heat tolerance of aerobrakes which are still at a wimpy 1.2k.

The ships also cost more then in 1.04 to get working. I wish this wasnt the case because i prided myself on them being an economical alternative to launching the payload as a rocket. It took longer to get it up there, but it would cost a few thousand less. Now, I feel they have lost their efficiency, though i have not tested how cheep i can get up a 36t payload via rocket in 1.05...

AND PLEASE SQUAD DON'T MAKE ME HAVE TO DO THIS ALL OVER AGAIN IN A MONTH FOR 1.1

to my surprise i did not notice a big difference between before and after the body lift fix; and it is a decent size spaceplane

Edited November 13, 2015 by fireblade274