Mecjeb problems

[qbert]

I have played KSP almost from it's inception and have used mechjeb and then mechjeb 2. I even found ways to make it work after the originator left the project. Then it was brought back to life and all seemed well until the latest KSP update.

The problem seems to be that Mechjeb is over compensating in the most recent update.

Firstly, there is an annoying yaw when you use two liquid fueled boosters. This can be dampened to some degree by turning the gimbal down to 10 or so buy it still present.. Is anyone else having the same problem.

Secondly, after a reinstall of a fresh copy of mechjeb I can't even get into orbit. for some reason it tends to over correct in the gravity turn and flips over. Rockets that I flew before are now unflyable using Mechjeb. is anyone also having this problem.

 

 

[Snark]

Moving to Add-on Discussion.  But if you have an issue with a specific mod, you're probably best served by posting in the thread for that mod-- it's where the folks hang out who'd be most likely to be able to answer your questions.

 

[Jas0n]

For the gravity turn problems, try setting the start point to a lower altitude. I think the default is still the same as what it was before the aerodynamics change.

[Spricigo]

Maybe the culprit of the problem is  not MJ, but something that changed in the game update. 

Have you launched the without MJ before and after the update?  

Also is it happening with a (/few) particular craft or to all your vessels?

If you think it may be a craft related issues post a picture (with CoM displayed preferable)  so people may try to diagnose the problem and help you figure out a solution.

[genericeventhandler]

it's probably your control surfaces, turn everything down to 40% including Gimbals.  It was a change in 1.2 that affected everything that gimbals or deflects. 

 

 

[qbert]

I have restructured the rocket to bring it in line with real world setting, ( CP 1 diameter lower than CG), It actually was not far out. I activated RCS during launch, I lowered the start of the gravity turn, I turned everything except RCS down to 20% including Gimbals, and it still happens except in a less dramatic fashion. Prior to making the above post I had added fins which I have seldom use and it made the overcompensation much more dramatic even with the controls turned down to 20%.

I reduced the gravity turn from 6km where I have always had it to the default 3.4km

To answer some of the other questions, it is doing with all my rockets.

Video of a launch is coming, I just need time for Vimeo to process it..

[qbert]

Here is the video showing over compensation.  https://vimeo.com/225151553/64d425877c

 

 

Edited July 11, 2017 by qbert

[genericeventhandler]

Can you post a .craft file of the rocket and I will launch it and see,  those fins look really tiny though.

[danielboro]

i see this too
i only moved to 1.3 2 days ago
ships that i used in 1.2 now wobble during node burn
but this cold be a change in KSP and not MJ

[qbert]

I agree with danielboro and that was the reason I asked in the other forum but the moderator bumped me down here. I have no way of adding the craft file to the forum post but I really doubt it's the rocket anyway, I have flown this version dozens of times prior to the update. My belief is that something in the update is either giving Mechjeb the wrong numbers to work with or Mechjeb is for some reason not reading the right values..

[Spricigo]

9 minutes ago, qbert said:

I agree with danielboro and that was the reason I asked in the other forum but the moderator bumped me down here. I have no way of adding the craft file to the forum post but I really doubt it's the rocket anyway, I have flown this version dozens of times prior to the update. My belief is that something in the update is either giving Mechjeb the wrong numbers to work with or Mechjeb is for some reason not reading the right values..

You may ask him to move the thread back to Gameplay Question(use the report in your own post, send a Pm or just say " @Snark, may you move the thread for me?" or create new thread there and reference this one.

 

Oh, and yes it seems to be something different with the game. Other people reported similar problem without MJ where the SAS is causing the problem. The vessels are still flyable (manually) if one keep closer to prograde but that is not what happens with the assisted flight.

[danielboro]

and i can add KOS to this

i just lunched a ship i made in 1.1 and use it for all my tourists missions (in 1.1, 1.2 and know 1.3)
and KOS is doing the same thing

i had to lower the gimbal to ~30%

[qbert]

Good new maybe. After many hours of investigation and using only two mods at a time, Mechjeb and another mod along with a fresh install I was able to find at least part of the culprit, KW Rocketry Redeaux. I have now loaded my all mod packs that I use minus KW rocketry and so far have encountered no problems that I was having before.

I am so disappointed that it was KW causing the program as I really enjoyed using some of the parts and ships.

Robert

 

[Tex_NL]

KW Rocketry Redux is perfectly compatible with MechJeb.

Just make sure you've installed the correct version. https://spacedock.info/mod/531/KW Rocketry Redux

[qbert]

Well I guess I spoke too soon. Further testing show that while KW rocketry exaggerates the yaw and pitch problems, it may in fact not be the cause.

 

To Tex_al. I had and still have no intention of bad mouthing a mod, however, there is at least one problem, the elastic struts, unless fixed within the last day or two, and may or may not be a manifestation of the problem some others, including myself are experiencing. And yes sir, as of 3 days ago when I dove into trouble shooting this problem I was up to date from the correct down load site for KWRR.

 

Robert

 

 

[Valdar]

Hi there!

I seem to be having similar problems, Mechjeb keeps overcompensating in the yaw axis and can't seem to decide that it's pointing at the maneuver node that I painstakingly set up for it. Only seems to affect >1 engine craft performing long burns. 

 

Turning on differential control under utilities helps to stabilize the burn but I still need to tap timewarp on/off sometimes when warping to the next maneuver.

[danielboro]

its not just MJ

all auto pilots have this problem now

its a change in KSP

[qbert]

I would have to agree, I sure hope someone in the KSP programing department is aware of it.

[Vanamonde]

Since this appears to be a wider issue involving more than one mod, the thread has be relocated to modded support. 

[Spricigo]

On 23/07/2017 at 3:01 AM, danielboro said:

its not just MJ

all auto pilots have this problem now

its a change in KSP

Of course it affects all autopilots.  Its something that change in 1.3 update.