Parts becoming detached in flight and space

[John Sheppard]

Hi this should probably  be in support section but not sure if in modded or un-modded 

I have some strange issues mainly when I make really big rockets 

1. If I set the Kickback SRBs autostrut to anything but heaviest part , then when I decouple them everything seems fine until they fall to around 100m behind my rocket. At which point there is a fast shaking and somehow my rocket becomes detached.  It still looks like its attached but the camera pans to the top half and I have no control over the engines at the bottom half

2. When I have a 5m fairing between an S3 tank (on top)  and S4 tank (under)  same detaching issue like above even though I select "rigid attachment on" set autostruts to heavy and manually add a bunch of struts the fairing almost always detaches from the S4 under it usually at around 10km mach 1

And 3rd.  Trying to get 200 ton ship to Dina orbit but during the long transfer when I press "warp here" and go in map view an asteroid (?) symbol flashes on my ship and sometimes when warp is finished half of the ship is few meters behind the other half. 

This last Issie started happening only after I put a telescope in sun orbit and then put a class E asteroid in 100km Kerbal orbit

 

My mods are only Engineer redux, docking port alignment, waypoint manager and transfer wrindow

[bewing]

What version of the game?

Yes, this does sound like a mod issue, because I haven't heard of this happening for the stock game.

It sounds like you think the craft is stock (which is good). So if you can use any file-sharing cloud server (kerbalx, pastebin, dropbox, etc.) to post your craft then our best bet is to try it ourselves and see if any of us can also make it fail.

 

[Gargamel]

7 hours ago, John Sheppard said:

1. If I set the Kickback SRBs autostrut to anything but heaviest part , then when I decouple them everything seems fine until they fall to around 100m behind my rocket. At which point there is a fast shaking and somehow my rocket becomes detached.  It still looks like its attached but the camera pans to the top half and I have no control over the engines at the bottom half

Sounds like a staging issue.   You have dropped your boosters, and you also somehow staged the next stage up.   Pics would help Dx this. 

[John Sheppard]

3 hours ago, Gargamel said:

Sounds like a staging issue.   You have dropped your boosters, and you also somehow staged the next stage up.   Pics would help Dx this. 

Yes this is exactly how it looks and behaves like..  As if the liquid boosters are staged along with the solid ones but due to having fuel keep firing without any control.  BUT it only happens after the SRBs "fall" some distance behind the rocket as if some invisible struts keep pulling the rest of the rocket down , breaking it

 

Only happens when the SRB autostrut are NOT set to heaviest part. Also doesn't seem to happen all the time but usually does with freakishly big rockets (7megatons on launch) 

 

Other 2 issues persist.  I will try to upload pics.  I got one design to reach orbit in one piece after few hours of trying different builds (didn't save the faulty ones)  was just wondering if anybody heard about something similar.  It is easy replicate this "detachment "(snapping?) by pointing 10 degrees outside the prograde marker.  At least for me that's almost guarantee to "snap" the rocket which seems logical but for me it happens sometimes even when pointing dead center of prograde 

 

Game version is 1.5 and only using stock parts 

 

Edited December 15, 2018 by John Sheppard

[John Sheppard]

Ok i so i tried again on a clean install (coppied the save file) where i only added engineer redux 

The launch went perfectly fine so i proceeded with the transfer burn to duna but while time warping the same asteroid icon kept following and rapidly flashing on top of the ship in map view and stopped when time-warp ended just like before

Also might be related but the Launch Sites icons migrate from Kerbin to somewhere between Kerbin and Eve during the timewarp not sure if it's important

I did a correction burn just after escaping Kerbin and set my Duna periapsis to 50km , after the timewarp ended and i was aproaching duna SOI the periapsis ended up inside the planet . I did have some variation in my other career but nothing that extreme was at most 5km

Anyways i ajusted the periapsis to 20km after entering SOI deployed fore and aft inflatable heatshield , did the aerobrake , jettision aft heatshield that was protecting the engines at 45km and started capture burn pointing mostly retrograde with a bit of radial in to raise my periapsis at the same time. SAS was engaged in stability mode everything was going fine for about a minute or so untill suddenly without any apparent reason camera shook violetly and the fairing base detached from the S4 tank-engine block under even tho both had rigit attachment on and autostruts (Pictures bellow)

http://prntscr.com/lvn8iz

http://prntscr.com/lvn92b

 

And Craft file : https://kerbalx.com/JohnSheppard/Duna-Lifter-3 (don't know if it works this is my first time using kerbalx also the picture was not added by me) 

The stages for Duna landing phase are not correct but that's because i would be opperating them manually with action groups repeatedly switching between engines as required . I built it this way because after doing capture burn and raising periapsis it's supposed to jettision the 4 relays 2 for polar orbit 2 for equatorial . Then the "mothership" will get into 80km orbit , detach the wheeled base (it has so much fuel to be able to change biomes and even get into orbit just incase) . Then i would dock the small lander back with the S4 engine block and wait in orbit untill the base completes it's mission on the surface