Interesting Phenomenon in Assemblies

I saw a very interesting phenomenon in assemblies today. Someone had
built a model of a linkage with a hydraulic cylinder driving it. When
the hydraulic cylinder was added in, the model started to disassemble
itself when it was simply rotated graphically. The problem turned out
to be that the joints that the cylinder were mated to were ever so
slightly out of parallel. The measure command gave angles on the order
of .000000082 degrees. The revolute joints on either end of the
cylinder were connected through several levels of subassembly to each
other.

When this assembly was rotated the cylinder would sometimes end up a
kilometer or so away from the main assembly. Parts of the assembly not
even connected to the hydraulic cylinder would end up "exploded" from
the main assembly and they would stay that way even through a forced
rebuild.

I just wonder if anyone else has seen this kind of thing.

 

No the cylinder was made in house in great detail. Flexible or fully
defined, the problem still existed.

I can understand the very small angles causing the constraint solver
fits, but how this got to mess with the graphics is another thing.

 

I have a spaceball, but this was on another engineer's system.