Why is Inventor Constantly Freezing?!? - Wait, it's not Inventor's Fault!

Earlier, this month, I relived. something many CAD users have experienced.

Frequent freezing and crashing!  The bane of any CAD jockey!

When a CAD system crashes, this is what designing feels like.

Let's paint a picture!

A natural first reaction is to blame the CAD system, then perhaps the hardware.  Next may come the universe and any crimes you may have committed in a past life that have resulted in such Karmic retribution.

But there was one thing that blew everyone of those theories out of the water.  Well, except for the Karmic retribution theory.

Inventor hadn't been having this problems before.  It had been rock solid in the days, even hours.

So I traced back to what I was doing when the freezing and crashing started.  What had I done?

It turned out, I had imported a step file that represented a gearbox. A coworker confirmed that he'd experienced the same thing on his system with that same model.

Smoking gun located!

This was my culprit.  You evil, evil model. 

Confirming the Symptoms

Opening and inspecting the gearbox by itself, There were a few symptoms the model exhibited that indicated it as our sick file.  One of them may not be a problem, but together, things start to click.

1) The size was larger than I expected.  It was about 5MB.
2) The file took forever to perform even simple operations.  Things like placing constraints in an assembly, or creating a sketch in a part took several minutes to calculate.
3) Then aforementioned locking up and crashing.

At this point, I was sure I had found my culprit.

The Solution

I recalled a discussion with a colleague many years ago, I remembered a corrupt step file that had caused crashing in her system.

In that case, there was a weird, intersecting face that crashed the system.  The solution there had been to locate it and cut it away.

I actually tried that, but after about an hour, I hadn't located the problem.  I even tried loading the file into Fusion 360, and still ran into performance issues.

It was time for a different approach, which I should have tried in the first place, in retrospect.

I downloaded a new model!  But instead of a STEP file, I tried an SAT file.

And that worked!  The system was stable again.  It didn't crash again after that.  The file was less than 1.5 MB,

It feels good to be under way again!

The Conclusions

Bad or corrupt neutral files exist.  They're unavoidable.  Like a game of telephone, they can be caused by bad translation, bad imports, or sometimes, just bad luck. I couldn't tell you the cause of this models issue, and ultimately,, my superiors didn't care.

They wanted the project moving, they didn't care about which corner of the model had an issue.

I encourage you to be aware that "bad models exist!"

Some CAD models just fall in with the wrong crowd....

Moreover, when your program of choice begins crashing, remember that crashes aren't always the fault of the program.  Whether your using Inventor, Solidworks, Solidedge, or "My-CAD-Program-is the-best-and-if-you-disagree-your-wrong" CAD (We all know who those guys are!), look at what you did just before the crashing started.

It's always possible that whatever that was, a model, a bad constraint, sketch, whatever, is your "bad seed"

Keep your eyes open!




Photo Credits

photo credit: image29991 via photopin (license)

photo credit: L'hydrofoil via photopin (license)

photo credit: 45/52 Cat Burglar via photopin (license)