Hello,
I’ve got something of a problem… I’ve got a physics setup that is consistently misbehaving…
The setup is kinda complex… it has a number of stacked bodies, using configurable joints to keep them on the XY plane, and fixed joints so that they’re linked to each other (one is a “root body” with no fixed joint)
This stack works alright when it’s at the origin… it just sits there, until it becomes unbalanced and topples over… not a problem…
The problem is when this stack is propelled (it’s a rocket) to over 1000 units high on the Y axis… what happens there is that everything, all those rigidbodies, start wobbling and jittering out of control (like 1000 units/second out of control)… their velocities start changing constantly, and it’s clear that the physics simulation isn’t working anymore… This happens consistently… there is some variation of the actual point at which the madness starts, but if I leave everything without moving, it stays perfectly stable… could I be suffering from floating point inaccuracies? 1000 units seems too little for that…
As far as scale goes… All bodies are around 1 to 2 units large, with masses around 0.1 and 0.3… no linear drag is applied…
The bodies are propelled by constant forces applied to the lower bodies (children in the fixed joint hierarchy)… these seem to work fine, until, of course, the entire setup goes kablooye 
The Fixed Joints are set to break at 5 force and 5 torque, which would work very well, if the whole system managed to keep stable…
As for forces… I’m applying about 10-20 units constant force at a time…
I’m using capsule and box colliders on the bodies… the geometries for them are actually children of the gameobjects that have physics components attached, and is just there visually (I think)… none of the meshes have rigidbodies or colliders attached directly…
As far as the scene hierarchy goes, none of the bodies are parenting another. They are all on scene level… their “hierarchy” is solely based on the fixed joints
The colliders do intersect a bit while connected by the Fixed Joint…
For the physics settings, I’m using 16 iterations, gravity at default -9.81 and all other settings at default…
That’s about all I can say about my setup…
Can anyone shed a light on this? It’s driving me crazy… and it’s a core feature of the project, so it’s really important tat it works 
As always, thanks in advance 
Cheers
EDIT: did some more testing… raised all the masses and forces tenfold, just to see if it was a scale problem… no dice, it still does the same…
I noticed that it isn’t so much distance from the origin that might be causing it… it might have to do with acceleration… it seems after some sort of speed barrier is reached, the simulation goes nuts 
