Just in terms of feedback as to what other users do.
With translators sometimes you get files coming in off scale so that you import a metric modelled part into an inch unit file and get something that is scale up by 25.4:1 this is a problem best sorted out at the translation stage, and it is usually possible to do so.
Other times you get supplier parts that you don't need to create drawings or have any downstream use for. These if modelled in the wrong units are no problem whatsoever to use in your assemblies. We would simply use them as they are.
Very infrequently you get something modelled to the correct scale but in your no preferred units, and it is parametric. In those rare cases it remains reasonably difficult to change the units and yet keep the parameters. One way around it is that if you only need to use it in assemblies then it will do no harm to leave it as it is. You can also draw it in the opposite units if you wish without changing the model.
In short I would probably consider leaving the in the units as modelled unless there is an overriding technical need to change it. Most methods of changing it will either degrade the data by forcing you to lose the parameters or go to a lot of trouble re-modelling. Frankly NX handles mixed units quite well so the inconvenience involved or the mere fact that it goes against the grain are seldom matched by a strong technical imperative to change the units.
If the files you are receiving have to be translated into NX, then rather than open the file directly, I start a new part file with Inch units. Then do a File -> Import... If the original file was in mm, it will automatically be converted into in inches to match the units of your part file. I have had pretty good luck with this method. Occasionally however there is a part that won't scale correctly, as Hudson noted.
Also for some of the translators you may find altering the settings influences the outcome. Translated data more infrequently has any parameters so you're often fine just to scale up of down after you import.
Wow, I didn't think anyone would say THAT! In some ways, yes, but its a real pain if you need to relate information in both directions.
Not being able to set a different unit part as the work part is a dramatic limitation, and the workaround of creating another top assembly with different units is inelegant.
More often I have been taking the time at file translation to convert the part to inches.
In some cases, it may work out better to create a second part in inches then wave link the mm body in to maintain associativity. But then you still might have trouble with outputing modifications back to the original source.
