Is there anyway to open and edit 2007 files using 2006

I think you hit on it, most of us don't know how hard it is and how
much could go wrong. Hell, sometimes going up to a new version results
in feature failures. And many probably don't realize that some of the
underlying code for a feature changes from release to release which is
what causes these errors. Now imagine going back to a previous version
or two and the feature no longer has the code that made it work in the
first place. Perhaps it works and doesn't error but gives you different
geometry, it happens sometimes going forward, gonig back will be worse.
I would be scared to trust the model that's been saved back.

I do see two ways that may it could work on a smaller scale.

1. The file was simply saved in the new format but no update was
perform so everything should be as it was for saving back.

2. Save as an older version results in a dumb solid but maintains
internal id, face, plane, & axis names such that the model can work
with assemblies and not lose mates. I think this approach is a more
reasonable request and easier to program.

 

Solidworks has chosen that models will just automatically update when opened
in a new version, and I'm sure this includes using new algorithms if the
code for a feature has been rewritten.
This is not the way that all CAD vendors do it.
I-DEAS will continue to rebuild your models using the old algorithms, until
you explicitly choose to "migrate" each individual feature, and gives you
some tools to indicate whether this is likely to give you a problem or not.

I think the reason I-DEAS was made to work that way is that it has always
been used to make the most complex types of solid and surface models
possible, and so the likelihood of a rebuild failure is higher than for
simple prismatic geometry.
In contrast, SWX has traditionally only been used to construct simple
geometry, and it's only relatively recently that it has started adding
surfacing tools to construct more complex forms.

Maybe it's time for SWX to give more control over what gets updated under
new versions of software.

John H

 

It seems they do some of both. I've had mates that error out
(over-define) on a new version and can't be fixed....recreating the
exact same mate then fixes the problem. In this cases it looks like a
bad combination of the old mates code and the mate solver. Apparent the
mate type's code change and thus the newer code works.

When you open a part, it does so without errors. However, on a Forced
Rebuild, the errors show up. Same thing, rebuild the feature will often
fix it. So it appears that each feature has its own code, then there
are the solvers and geometry checkers and while some change and others
don't, certain combinations of the two throw up errors.