Walking assembly

[Toybuilder]

I've recently experienced a problem where a sub-assembly likes to walk on its own with each regeneration of the sub-assembly or of the parent master assembly.
Video:

I don't see any inter-design relationships in the tree that might explain it... Nor any planes/axis definition or relationships.

There appears to be some circular relationship that I have introduced into this model. Is there any way I can figure out how?

 

[HaroldL]

Do you have the first part/subassembly constrained to the origin or default planes of the assembly workspace?

 

[Toybuilder]

Do you have the first part/subassembly constrained to the origin or default planes of the assembly workspace?

Yes, I have various other sub-assemblies anchored.
I inserted a duplicate of the assembly that walks and it doesn't walk. I think I'll work around this issue by removing the original instance... Still, it would be good to know how/why this happens so that I don't do it again!

 

[DavidJ]

Do you have a 3D mouse connected? I occasionally get some odd movements if something is resting against my 3D mouse, or if it needs a re-calibration.

 

[Toybuilder]

I do have 3D mouse, but the behavior isn't that view of the model is moving -- the subassembly moves in the model space.