As with everything, not really understanding something leads to
its removal within an environment. This is a story I have
heard many times and what i have learned over the years may
The root of the issue is the modelling kernel and its inability
to cleanly reroute BRep, solid works tends to be better than CATIA
at this. CATIA has the ability to semi-automatically
map the BRep based on distance between the old and new geometry's ,
but its not perfect.
Secondarily the users are not using the Replace function when
editing geometry, this will remap the BRep IDs and allow the
changes to somewhat transparent.
Thirdly When Engineering Connections (Constraints) are created
we must always create them to published wireframe geometry not the
BRep of the model, because we cant guarantee that the Kernel or the
Designer will reroute the BRep.
Ultimately the Engineering Connections fail due to the BRep ID's
The best solution is to not use any geometry from the models'
themselves, but to construct a Skelton that defines the motion and
link this geometry to each of the designed parts and republish
it. We can then use this geometry to create the engineering
connections and kinematics if required. Further more if i
change the skeleton then the parts will update, the engineering
connections will resolve and the if there is kinematic motion this
will also update.
This structure provides support for motion, in this model
the MSTR Skeleton lays out the motion wireframe / interfaces.
We then publish these and link them down to each sub assembly's
Slave skeleton where they are need and republished. The
engineering connections are then created between the publications
of the slave skeletons. Finally the motion created.
Note we have not yet created any designed parts, so we have two
choices we can insert into the sub assemblies STD Components, or
FST's. When the motion is run these will now move because
were moving the assembly that they are within. Or we can use
design in context, by inserting a new part below one of the sub
assemblies and linking the wireframe geometry from the slave
skeleton to the newly inserted part and then design based on these
You could flatten the structure if you don't have motion.
Hope this makes sense, if you have any questions let me
See attached Video
Static Components Product
Slave Skeleton 1
Moving Components Group 1 Product
Slave Skeleton 2
Group 2 Product
Slave Skeleton 3