Mining Craft experiences the Kraken when loaded with Ore

[Rrday-4]

So this is a rather strange issue I have recently come across that is frustrating me. I have a ship that works perfectly well but once there is Ore in the 4 tanks from mining and I attempt to leave Minmus for my Refining station My craft experiences a Kraken Wobble that tears the ship apart shortly after take off.:mad:

I have tried some trouble shooting myself with no success. Odd thing is I believe it is a clipping issue but when I allow clipping in the Debug it still fails. I've also looked at it and I don't see much Clipping with the tanks. It works perfectly fine with the ore containers empty and with only 2 filled but 3 or 4 clearly anger the Kraken. I've even tried all of this with SAS enabled and disabled encase it was causing the wobble.

I am aware of the clipping with the drills but I don't understand why this would only relate to 2 containers with ore and not the other two...

I would like to fix and refine this mining craft before using it for a mining mission on Duna. Plus we all want to save Jeb's good bud Bill from being killed by the Kraken!:)

Craft file, and Game file are in the link below. I have also included an Image of the Aftermath:

[URL]https://www.dropbox.com/sh/cdzaz78esqp2znh/AAAx7i-cdenH7YM75pCDCZvwa?dl=0[/URL]

[diomedea]

Not really a Kraken. If that miner had struts keeping the ore tanks in position, those would not be wobbling and no destruction would occur (tested with a full Ore load).

Allow me to explain. KSP, though not perfect, has some realistic physics. Among else, physics routines compute at each frame the forces between parts. When those ore tanks are full, their mass drastically increases (by 3 tons each!). Those tanks are connected to the ship only through the top joint, to a RCS tank each. That joint is robust enough to keep the empty tanks (0.5 ton) but not the full ones (3.5 tons), when the ship accelerates.

The solution is really to use struts connecting the base of each tank to the rest of the ship. I put 2 struts for Ore tank (8 total) connecting the Rockomax 2.5m tank at the base, and that modded miner ship works no problem.

[Clouds]

Disclaimer: I haven't actually loaded your craft. The following is some general info that I'm guessing might be relevant:

For quite a while in KSP, I've noticed that crafts' parts can enter into an amplifying resonant wobble of inevitable death (A.R.W.O.I.D? :cool: ) if a very heavy single part is attached to a very lightweight part: for example, trying to hang 4 orange fuel tanks off a probe core. Strutting the supporting part, or the heavy parts, or choosing a supporting part of more similar mass to the heavy parts, will guard against the wobble. My best guess is that this has something to do with the physics simulation simply not being able to cope with this kind of setup.

2 full ore tanks probably weigh little enough; 3 full ore tanks probably surpass that unknown breaking point where the physics go wacky.

I had this problem with a conceptual ore-filled space station I was trying to launch, where I didn't want to strut everything in order to save on part-count. It would shake itself to bits. Ore tanks are extremely heavy especially for their size; it can be deceptive.

[B]TL;DR[/B] try strutting your ore tanks or the part they're attached to, or even just strut them together.

[Rrday-4]

Thank you, that makes a bunch of since! I guess I never really considered the loading difference. Out of curiosity will that also be a problem with my refining station I have orbiting? I have no intention of moving it from Its orbit but don't want to start filling it with Ore only to discover it is also flawed. It wont move, but things will be docking to it so I wonder if the physics of docking will cause that same issue to occur. There are 12 small ore tanks on that station only attached to Hexagonal Struts.

Again thanks for you help.

[SgtSomeone]

I also find I can develop wobbles as the SAS overreacts and over-corrects with rocket gimbal and reaction wheels. In addition to strutting, you can also try turning SAS off for a second, and then re-enabling when everything stops wobbling like a bowl of jelly.