Galane Posted January 10, 2014 Share Posted January 10, 2014 I've used stacks of fuel tanks and struts to brace upper parts of rockets, then used sepratrons and upside down decouplers to dump them as they emptied. The tough part was having to leave some hanging on empty until the rocket would make it through the gravity turn. Then the last pair of bracing stacks could be dumped.I should launch some of those with KJR to see how they work now. Link to comment Share on other sites More sharing options...
Darth Lazarus Posted January 10, 2014 Share Posted January 10, 2014 why did i havnt seen this mod earlier? ... on the oen hand, i prefer to play in stock-only mode with some help from engineer and RCShelp plugins for build. but after version 0.20 i got problems with my proton rocket. still flying fine BUT with some wobble. going to test with this mod now to see the rsult, if flying is better or worse ^^nevertheless thanks a lot for the work. Link to comment Share on other sites More sharing options...
InfinityArch Posted January 10, 2014 Share Posted January 10, 2014 Hey, does this mod still cause odd behaviors in the landing gears from B9 aerospace? Link to comment Share on other sites More sharing options...
ferram4 Posted January 10, 2014 Author Share Posted January 10, 2014 I'm not aware of any odd behaviors with landing gear from B9; I haven't heard any complaints about it, so I don't think it does. Link to comment Share on other sites More sharing options...
Razorcane Posted January 11, 2014 Share Posted January 11, 2014 I really wish this mod worked, because then I could avoid using struts. Unfortunately, here is what happens with the mod installed. It is the exact same without the mod.The Rocket, uses 3.75m parts.The rocket, after take off.Those tanks seem to not want to stay together, even with struts. Now, if I take the mod off, the struts hold it firmly in place. However, this mod seems to flat out break everything. Now, you might want to say that it's because I'm using too many launch clamps, but the problem doesn't seem to occur when I only use two fuel tanks. So, what's going on? I really don't believe that the mod is broken, otherwise this issue would have been fixed a long time ago, or the project would have been abandoned. Link to comment Share on other sites More sharing options...
ferram4 Posted January 11, 2014 Author Share Posted January 11, 2014 Okay, so Launch Clamps are breaking something then. I will investigate and look to see if I can fix the issue.That said, the issue looks like it happens at decouplers, so I have a hunch what's going on there. I'll see if I can find the problem. Link to comment Share on other sites More sharing options...
Razorcane Posted January 11, 2014 Share Posted January 11, 2014 Wait wait wait. No one else has had this issue? It's possible that there is some problem with KJR and RSS, though I'm sure you covered all your bases. Anyway, thanks for taking a look at it. Also, it starts spinning wildly out of control. Of course, that's possibly because of the issue above, or it's something else entirely. I'll have to work on that. Link to comment Share on other sites More sharing options...
ferram4 Posted January 11, 2014 Author Share Posted January 11, 2014 I can see it being an issue with the engine stiffnesses... basically, since KJR calculates joint stiffness based on the part's model, if you connect an upper stage with an engine much smaller than the tanks of the upper stage and the lower stage the engine-decoupler connection can be quite weak. I've noticed some wobbling myself, but I have been busy engaging in wretched excess in RSS, so I figured it was understandable.I'll do some more testing, but I think part of the issue might be that decouplers are being overzealous in deleting joints when they shouldn't; an understandable situation given the early joint issues the mod had. Link to comment Share on other sites More sharing options...
Galane Posted January 11, 2014 Share Posted January 11, 2014 Wait wait wait. No one else has had this issue? It's possible that there is some problem with KJR and RSS, though I'm sure you covered all your bases. Anyway, thanks for taking a look at it. Also, it starts spinning wildly out of control. Of course, that's possibly because of the issue above, or it's something else entirely. I'll have to work on that.With that big, bulbous fairing on top and no fins on the bottom, it likely has a problem with the position of the center of pressure being in the wrong place, which should be (IIRC) 1 to 1.5 diameters behind the center of gravity on a single tube rocket like that.Whatever the rule may be for the weird assemblies possible with KSP, the center of pressure always has to be behind the center of gravity/mass. A plugin to add a center of pressure display to the VAB would help a lot with constructing stable rockets. Link to comment Share on other sites More sharing options...
InfiniteDice Posted January 11, 2014 Share Posted January 11, 2014 32 orange tanks... moments before it collapsed! Link to comment Share on other sites More sharing options...
localSol Posted January 11, 2014 Share Posted January 11, 2014 [...] I have been busy engaging in wretched excess in RSS [...] Amazing album! The old orange tank looks so tiny. The novapunch launchers years ago were big. This is hugemongous! Link to comment Share on other sites More sharing options...
Zander Posted January 11, 2014 Share Posted January 11, 2014 I have been having the same issue as razorcane. Decoupling anything, even a launch clamp weakens everything to spaghetti. Without decoupling it is very nice though. Link to comment Share on other sites More sharing options...
LameLefty Posted January 11, 2014 Share Posted January 11, 2014 I I have been busy engaging in wretched excess in RSSThat SLS-esque beast is impressive. Thumbs up. (Now, what is "RSS"? ) Link to comment Share on other sites More sharing options...
AbeS Posted January 11, 2014 Share Posted January 11, 2014 Real Solar System mod by Nathankell Link to comment Share on other sites More sharing options...
Razorcane Posted January 11, 2014 Share Posted January 11, 2014 With that big, bulbous fairing on top and no fins on the bottom, it likely has a problem with the position of the center of pressure being in the wrong place, which should be (IIRC) 1 to 1.5 diameters behind the center of gravity on a single tube rocket like that.Whatever the rule may be for the weird assemblies possible with KSP, the center of pressure always has to be behind the center of gravity/mass. A plugin to add a center of pressure display to the VAB would help a lot with constructing stable rockets.I don't think that's the issue, since I said that using two tanks(or even 1), instead of the 5 or 6 that it currently has fixes the problem.I can see it being an issue with the engine stiffnesses... basically, since KJR calculates joint stiffness based on the part's model, if you connect an upper stage with an engine much smaller than the tanks of the upper stage and the lower stage the engine-decoupler connection can be quite weak. I've noticed some wobbling myself, but I have been busy engaging in wretched excess in RSS, so I figured it was understandable.I'll do some more testing, but I think part of the issue might be that decouplers are being overzealous in deleting joints when they shouldn't; an understandable situation given the early joint issues the mod had.There's only one decoupler on the rocket, and it's the 3.75 one from KW. I made sure to strap the upper stage inside the fairings with lots of struts, so there's absolutely no movement. The only movement comes between those two copper colored tanks you see in the middle of the first stage. Link to comment Share on other sites More sharing options...
NathanKell Posted January 11, 2014 Share Posted January 11, 2014 Razorcane: launch clamps are decouplers. Link to comment Share on other sites More sharing options...
Starwaster Posted January 11, 2014 Share Posted January 11, 2014 I can see it being an issue with the engine stiffnesses... basically, since KJR calculates joint stiffness based on the part's model, if you connect an upper stage with an engine much smaller than the tanks of the upper stage and the lower stage the engine-decoupler connection can be quite weak. I've noticed some wobbling myself, but I have been busy engaging in wretched excess in RSS, so I figured it was understandable.I'll do some more testing, but I think part of the issue might be that decouplers are being overzealous in deleting joints when they shouldn't; an understandable situation given the early joint issues the mod had.Since there was wretched excess involved, of a Kerbal-like nature, you're forgiven. Link to comment Share on other sites More sharing options...
Razorcane Posted January 11, 2014 Share Posted January 11, 2014 Razorcane: launch clamps are decouplers.Oh...I thought he meant actual decouplers. Woops. Link to comment Share on other sites More sharing options...
Galane Posted January 11, 2014 Share Posted January 11, 2014 What worked to help stabilize rockets and make them less wobbly before KJR was to have one or more engines in the first stage that either didn't have gimbal steering or locking the gimbals of some of the engines. I'd just lock one big engine in the center and let all the rest do the steering.Try putting three LV-T30 engines under small tanks around the bottom, with fuel pipes running to and from the center tank. If that doesn't seem to change anything, use LV-T45 engines to steer and lock the main engine. Might need 4 or more LV-T45's to steer that rocket during boost phase. Either way it'll improve first stage TWR. When the rocket gets through the gravity turn (and if it hasn't folded up or gone for a spin) you can manually drop those. It's very useful how looping fuel pipes in and out (but *not* around) keeps the engines running but still empties the outer tanks first. Link to comment Share on other sites More sharing options...
ferram4 Posted January 11, 2014 Author Share Posted January 11, 2014 (edited) Ah, I see what the problem is; you're using multiple tanks on the first stage when you don't need to and the wobble is being caused between the smallest ones. There's some weird thing in KSP's physics, that I don't know if it's caused by PhysX itself or Unity's implementation of it where joint forces seem to be scaled down to the lowest mass object's size. You'll notice that most of the flexing in stock KSP occurs at decouplers, which are the lightest objects in stock KSP. So the same thing is probably happening here.The only solution I've been able to find is struts. Hell, the "decoupler stiffening" is simply adding strut-like joints.Edit: I think I found the issue. KJR's mass threshold is culling out the stretchy tanks because they're too light when dry. This would explain why it primarily happens in RSS. I'll look into fixing this and hope it won't break anything. Edited January 11, 2014 by ferram4 Link to comment Share on other sites More sharing options...
Ringkeeper Posted January 11, 2014 Share Posted January 11, 2014 As there was yet no answer: wobbling "Sr. Docking Port" normal or not covered by the mod?Because i have alot of problems with them.Examplescreen:http://www.ringkeeper.de/screens/fuelstation.pngA : 5 Tanks welded together (so 1 part) connected with "Sr. Docking Port" toB : some trusses welded together (so 1 part) connected with "Sr. Docking Port" toC : 2 Karmony Station Parts connected with "Sr. Docking Port" at the moment toD: Fuel shuttleeach arrow 2 docking portsIf i would now start pushing with the fuel shuttle the whole thing would bend at the ports and break. Link to comment Share on other sites More sharing options...
ferram4 Posted January 11, 2014 Author Share Posted January 11, 2014 Lots of mass on either side of the docking port, combined with decently high thrust, combined with the fact that it looks like in most of those places you've put lots of other smaller parts next to the docking port means that it's basically set up to wobble as much as possible. There's only so much that can be done.That said, it looks like I was right about stretchy tanks being skipped. I'll look into getting a fix out after my testing confirms no odd side-effects. Link to comment Share on other sites More sharing options...
KhaosCorp Posted January 11, 2014 Share Posted January 11, 2014 Has anyone else been getting random hitchhiker launch clamps?? I know its caused by KJR, but not directly, interaction with something else...but I get no log errors or anything, so kinda hard to trace it down. Its by no means gamebreaking, most time no harm comes when it happens, just curious if anyone else has seen this..if so what other mods you running...would like to track this down. Link to comment Share on other sites More sharing options...
Zander Posted January 12, 2014 Share Posted January 12, 2014 (edited) Lots of mass on either side of the docking port, combined with decently high thrust, combined with the fact that it looks like in most of those places you've put lots of other smaller parts next to the docking port means that it's basically set up to wobble as much as possible. There's only so much that can be done.That said, it looks like I was right about stretchy tanks being skipped. I'll look into getting a fix out after my testing confirms no odd side-effects.Ferram.. I think whatever is causing the problem is solely with decoupling. I have stretchy tanks and a huge rocket and it works very well when I launch with no launch clamps. The act of decoupling anything including the launch clamps seems to turn off KJR and make the rocket go back to stock wobblyness.EDIT: Cancel that, I am sorry. I just did some more testing and found it is not caused by decoupling, i am getting the problem even with no launch clamps with the latest version of KJR.Furthermore, with my current rocket. There does not seem to be much difference between having and not having KJR installed.and one of the main sources of bending seems to be procedural fairing bases. its like KJR has no effect on them. This is with KJR and like 16 struts. At this part Ferram im seriously starting to wonder if it wouldnt be better to just disable bending joints and just make them break only.In real life a rocket joint will either not bend more than a few milimeters or break and have a catastrophic explosion.There is no real life situation where you can have a joint separating on one side by like 10 cm and then somehow magically coming back together with no lasting effect on the rocket.in a situation like that the rocket is toast anywaysSo I think just disable joint bending and let joints either break or be locked rock solid. reducing bending doesnt seem to work. Edited January 12, 2014 by Zander Link to comment Share on other sites More sharing options...
iVG Posted January 13, 2014 Share Posted January 13, 2014 I have the same problem. The plug-in used to work (v1.4 was the one I used before) but not any more... Link to comment Share on other sites More sharing options...
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