Virtualgenius Posted August 19, 2013 Share Posted August 19, 2013 Having problems with mechjeb landing always 200m off target old version was always on the money 1 to 5 m away anyone else experiencing this its the latest version Link to comment Share on other sites More sharing options...
ASW122 Posted August 19, 2013 Share Posted August 19, 2013 This sounds like you have fuel imbalance causing your ship to go sideways. before it crashes check and make sure the tanks are draining uniformly and not causing the center of gravity to shift in flight.Definitely not fuel imbalance. I tried it again with my favourite heavy hauler (nothing special about it, just an asparagus launcher, I just like it for its reliability). I can get that design to orbit by just turning on SAS and firing the stages until I have to burn to turn the launch trajectory into an orbit. Even if I launch it and do the start of the launch manually, as soon as I turn on the the MJ on and it starts tipping, the higher it is, the faster it tips. Initially I thought it was going for gravity turn (normally when I fly it, I don't start widening my launch trajectory into an orbit until I'm near my launch apoapsis), but it was way too low (if I have it enabled from launch I see it start tipping at 700m and never get above 5k) and the readout still read "vertical ascent". Link to comment Share on other sites More sharing options...
Vertibirdo Posted August 19, 2013 Share Posted August 19, 2013 Definitely not fuel imbalance. I tried it again with my favourite heavy hauler (nothing special about it, just an asparagus launcher, I just like it for its reliability). I can get that design to orbit by just turning on SAS and firing the stages until I have to burn to turn the launch trajectory into an orbit. Even if I launch it and do the start of the launch manually, as soon as I turn on the the MJ on and it starts tipping, the higher it is, the faster it tips. Initially I thought it was going for gravity turn (normally when I fly it, I don't start widening my launch trajectory into an orbit until I'm near my launch apoapsis), but it was way too low (if I have it enabled from launch I see it start tipping at 700m and never get above 5k) and the readout still read "vertical ascent".Check your AR202 case. It can be placed in different orientation. Game always uses AR202 by default to control your craft. You can also check if your command module is selected by "control from here" Link to comment Share on other sites More sharing options...
Keome Posted August 19, 2013 Share Posted August 19, 2013 Also, double check your accent autopilot settings. I once forgot to change it back from Mun launch settings, so it tried to circularize the orbit at 25km. with predictable results Link to comment Share on other sites More sharing options...
sojourner Posted August 19, 2013 Share Posted August 19, 2013 Definitely not fuel imbalance. I tried it again with my favourite heavy hauler (nothing special about it, just an asparagus launcher, I just like it for its reliability). I can get that design to orbit by just turning on SAS and firing the stages until I have to burn to turn the launch trajectory into an orbit. Even if I launch it and do the start of the launch manually, as soon as I turn on the the MJ on and it starts tipping, the higher it is, the faster it tips. Initially I thought it was going for gravity turn (normally when I fly it, I don't start widening my launch trajectory into an orbit until I'm near my launch apoapsis), but it was way too low (if I have it enabled from launch I see it start tipping at 700m and never get above 5k) and the readout still read "vertical ascent".Well, at this point I can only suggest installing a plain vanilla version of KSP and only adding mechjeb, then try launching one of the stock ships. If that works then start adding in any mods you have until it stops working. Link to comment Share on other sites More sharing options...
Xzabath Posted August 20, 2013 Share Posted August 20, 2013 Are any of the older versions of mechjeb functional?? Link to comment Share on other sites More sharing options...
GraviTykillz Posted August 20, 2013 Share Posted August 20, 2013 Mechjeb used to work great if you could load 1.9.8 and a version of KSP before the last updates. Link to comment Share on other sites More sharing options...
Toyotawolf Posted August 20, 2013 Share Posted August 20, 2013 Are any of the older versions of mechjeb functional??The Problem isn't Mech Jeb, lets get that straight for once and for all and for everyone, KSP changed how crafts work and the physics involved using reaction wheels, and Mech Jeb was not codded for this, Sarbian has attempted a fix for this and build 72 of the Dev build works ok enough, but you have to get used to not letting it do all of every function for you, sometimes you need to take the tiller so to speak. Link to comment Share on other sites More sharing options...
Starwaster Posted August 20, 2013 Share Posted August 20, 2013 The Problem isn't Mech Jeb, lets get that straight for once and for all and for everyone, KSP changed how crafts work and the physics involved using reaction wheels, and Mech Jeb was not codded for this, Sarbian has attempted a fix for this and build 72 of the Dev build works ok enough, but you have to get used to not letting it do all of every function for you, sometimes you need to take the tiller so to speak.QFT. And I think that if I can launch this monstrosity with the latest MJ2 then yeah, it works.Four KW 3.75 meter tanks w/Griffon XX to give you an idea of scale. They are bolted directly onto a gigantic fairing that completely surrounds the spacecraft at the center. The fairing is made with Procedural Fairings with a fairing base at the top and at the bottom where the engines are. It actually flies decently but it is ponderous. If it's kept fairly straight with no sudden course corrections then it flies. And that's what MJ is doing here. Nice and straight with no sudden moves. Link to comment Share on other sites More sharing options...
Virtualgenius Posted August 20, 2013 Share Posted August 20, 2013 I would say MJ works great just landings for me are way off course but I guess they will fix this and yes I am doing some minor course correction manually Link to comment Share on other sites More sharing options...
Toyotawolf Posted August 20, 2013 Share Posted August 20, 2013 I would say MJ works great just landings for me are way off course but I guess they will fix this and yes I am doing some minor course correction manuallyI wish they would but unfortunately the developer has gone dark and i'll keep saying it until proven wrong but they havent done any updates to the build in almost a month and prior to that it was quite regular again im talking dev builds and they havent said a peep in here since .21.1 was released. Link to comment Share on other sites More sharing options...
sojourner Posted August 20, 2013 Share Posted August 20, 2013 Yeah, R4m0n seems to have lost interest in the game. Hopefully Sarbian will find the free time to create a fork and continue the development. Link to comment Share on other sites More sharing options...
Nibb31 Posted August 20, 2013 Share Posted August 20, 2013 You guys are aware that we are in the middle of summer and R4m0n might just be on a well-deserved vacation... You might want to wait until september before declaring MJ abandoned. Link to comment Share on other sites More sharing options...
synik4l Posted August 20, 2013 Share Posted August 20, 2013 I agree with the people stating it works. It may not be perfect. But accents for me are great, landings are pretty decent(depending on ship and location of landing site). Docking takes forever but usually still works. To ASW122:Accent works pretty well for me. One thing i noticed on larger rockets is you need more RCS than you used to. MJ doesnt use SAS during takeoff(that ive noticed) to get into orbit. Thus if you have no RCS and your ship tends to be either top heavy, or just big in general. To where it tends to not stay pointed straight up. You will end up turning over. As MJ just cant control it, without having a bunch of RCS to work with. Also I dont change many settings. Final orbit 100 or 200. and i change my curve start to 10k meters. instead of 8. Hopefully this helps you Link to comment Share on other sites More sharing options...
Simplicity Posted August 20, 2013 Share Posted August 20, 2013 I agree with the people stating it works. It may not be perfect. But accents for me are great, landings are pretty decent(depending on ship and location of landing site). Docking takes forever but usually still works. I agree as well, while not perfect I can use ascent, maneuver mode, rendezvous autopilot, docking and landing all with next to no troubles at all (Unless I stuff things up myself) - I use Sarbian's dll as it's the most recent thing.. Link to comment Share on other sites More sharing options...
Doc Anderson Posted August 20, 2013 Share Posted August 20, 2013 For me, the landing issue with Mech Jeb (at least in 2.08) landing way off target turned out to be linked to auto warp. If I turned auto warp off before the deceleration burn, everything worked perfectly. Link to comment Share on other sites More sharing options...
Keome Posted August 20, 2013 Share Posted August 20, 2013 In my experience, Mechjeb's auto-landing can be messed up by things like warping (regular or physical), dropping stages in the middle of the deceleration burn to use a stage with a weaker engine (MJ won't recalculate for the lower thrust) or adjusting the landing coordinates after you click on 'Land at target'. Link to comment Share on other sites More sharing options...
Virtualgenius Posted August 20, 2013 Share Posted August 20, 2013 Well thats good to know I will turn auto warp off on landing and see how that works out Link to comment Share on other sites More sharing options...
Starwaster Posted August 20, 2013 Share Posted August 20, 2013 (edited) ok so, for the second time in a month I've spoken too quickly on a subject.there's definitely a launch issue with Mechjeb but maybe it just doesnt happen all the time.the rocket I posted a picture of, the same one I've had half a dozen successful launches of was just flown into the ground by MJ. I had reverted to launch because of a final stage mishap and now MJ has control inputs hard over for roll and yaw. there is no and hasnt been an MJ part on this ship, it's built into the RC-L01 module as its built into all my control modules. the ship is heavy but generally flies straight. The Navball is centered with sky showing.but The inputs just all get locked to extreme positions. here's the thing: if I press the appropriate keys then they 'unstick' and MJ tries to fly normally after that. Might be an issue with yaw, pitch and roll variables being initialized with bad values, or vectors not being properly normalized.FYI it behaved this way for TWO launches and on the third reversion stopped trying to fly the ship into the ground. No corrective action was attempted by myself, all I did was observe the problem, jiggle controls observe and then revert to launch. so it basically acted up for two flights and then go back to normal expected behavior. Edited August 20, 2013 by Starwaster Link to comment Share on other sites More sharing options...
Starwaster Posted August 20, 2013 Share Posted August 20, 2013 Well thats good to know I will turn auto warp off on landing and see how that works outalso, once the predicted landing and desired landing match up, try aborting and then click 'land anywhere' (not until after de orbit burns and high altitude course corrections) Link to comment Share on other sites More sharing options...
sojourner Posted August 20, 2013 Share Posted August 20, 2013 Accent works pretty well for me. One thing i noticed on larger rockets is you need more RCS than you used to. MJ doesnt use SAS during takeoff(that ive noticed) to get into orbit. Thus if you have no RCS and your ship tends to be either top heavy, or just big in general. To where it tends to not stay pointed straight up. You will end up turning over. As MJ just cant control it, without having a bunch of RCS to work with. Also I dont change many settings. Final orbit 100 or 200. and i change my curve start to 10k meters. instead of 8. Hopefully this helps youWhile Mechjeb does not use "SAS", it does use the reaction wheels. If your using RCS in atmosphere your doing it wrong. You should only be using control surfaces and reaction wheels to fly the craft before reaching space. Link to comment Share on other sites More sharing options...
synik4l Posted August 20, 2013 Share Posted August 20, 2013 I agree as well, while not perfect I can use ascent, maneuver mode, rendezvous autopilot, docking and landing all with next to no troubles at all (Unless I stuff things up myself) - I use Sarbian's dll as it's the most recent thing.. Same exact setup here. Cept ive gone back and forth between sarbs and stock. Not really sure whats better. But I will say. I think THE MOST COMMON mistake is "CONTROL FROM HERE". Everyone make sure you are controlling from a pod that is straight up. Or else it wont work. Link to comment Share on other sites More sharing options...
synik4l Posted August 20, 2013 Share Posted August 20, 2013 In my experience, Mechjeb's auto-landing can be messed up by things like warping (regular or physical), dropping stages in the middle of the deceleration burn to use a stage with a weaker engine (MJ won't recalculate for the lower thrust) or adjusting the landing coordinates after you click on 'Land at target'.This is all deff true...I never drop stages in the middle of a decent....Found it not working as well. Link to comment Share on other sites More sharing options...
synik4l Posted August 20, 2013 Share Posted August 20, 2013 (edited) While Mechjeb does not use "SAS", it does use the reaction wheels. If your using RCS in atmosphere your doing it wrong. You should only be using control surfaces and reaction wheels to fly the craft before reaching space.Interesting info. Looks like I need to rethink some of these top heavy rockets huh?edit: and when I say top heavy...I just mean things hanging out from the top...causing it to pull more from the top. making it alil harder to keep control Edited August 20, 2013 by synik4l Link to comment Share on other sites More sharing options...
King Arthur Posted August 20, 2013 Share Posted August 20, 2013 While Mechjeb does not use "SAS", it does use the reaction wheels. If your using RCS in atmosphere your doing it wrong. You should only be using control surfaces and reaction wheels to fly the craft before reaching space.It's not so much "wrong" so much as it is that RCS is terribly inefficient and ineffective at thrusting inside atmospheres; it's sort of like using an LV-N at ground level on Kerbin, crap thrust and crap fuel efficiency. Link to comment Share on other sites More sharing options...
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