I am, once more, struggling with assemblies in Solidworks.

I clearly don't understand them as well as I thought.

I have an assembly of 118 parts (some in sub-assemblies, so it's not as bad as it sounds), and all the mates are black.

I drag in a Toolbox Washer and it is mated using a concentric and a coincident mate, both to the same part. Once the dust has settled after the creation of these 2 mates, only 18 of the 155 mates in the assembly are black. The remainder are either a fetching shade of yellow or an angry red.

Clearly, the creation of a concentric and a coincident mate between a washer and a single fully-defined part cannot adversely affect almost every other mate in the assembly, so I can only assume that the problem lies somewhere else in my assembly, and that the insertion of the toolbox part has somehow triggered a full rebuild, thus exposing the problem.

The trouble I have is that, because I now have no idea what mate it was that caused the problem (because everything stayed black until right now), I have no idea of where to start to put it right.

This sort of thing happens quite often. It seems to me that, unless I can somehow force a full rebuild after each and every mate is created, I have no confidence that my assembly will not mysteriously fail at some time in the future.

My question boils down to this:

Is there a well-defined procedural workflow I can use to fault-find my failed assembly?

In the absence of such a workflow, I would need to suppress everything and sequentially resume component by component until the failure recurs. However, as I have already stated, the failure does not necessarily occur as the offending mate or mates are created, but at some future operation. How, then, could I be assured that my ministrations have resulted in a stable mates tree? I need a way to gain a sense of confidence in my Model Tree.

I would be grateful for some pointers here. I can't see that this specific problem would be covered in any training course, because it is clearly not the way the software is intended to behave.

I feel powerless to fix this problem, each time it occurs, because I seem to have no tools with which to investigate. Surely, I must be wrong, there must be a rigorous, repeatable way to troubleshoot mate issues.

SW2016, SP5  (but it behaved pretty much the same in 2014)

Cheers,

John

>>Edit:

I have fixed it now. It was due to a change I had made about 20 minutes and 10 Rebuilds ago. It only fell over at this apparently random point. Also, the problem was due to a single sub-assembly being unable to fulfil a single concentric mate. Why, then, did that cause 118 out of 155 mates to turn yellow or red? Why not just the broken one? And why not immediately?

Fundamentally, my question remains valid and important to me. What is the rigorous, repeatable workflow to fix this? I only found this one by random stabbing.<<