I have this problem frequently. My solution is to open up each sub part/assembly and for it to calculate the weight.
I think this problem is created when parts are included with sub assemblies. Sub assemblies don't have weight until it's forced to be calculated.
In my case every single in house fabricated part has both a part and assembly file for correct display of parts in parts lists. I don't want to change this threads focus so I will leave it at that.
Yes I am using templates that I brought in from a previous release. Hadn't considered that. I'll see if using the one's that came with ST8 instead.
My issue hasn't been with sub assemblies. Actually, when the part is in an assembly it's less of a headache for me because when I go to update all physical properties, it fixed the parts mass. It's when I'm doing a part that is not used in an assembly that I get aggravated.
Did you check the Automatic Update switch? I don't know how many times I see calls come through the system for mass being incorrect and it is because Automatic Updates are turned off.
After turning Automatic Update on you must update and save the file for the mass to be generated.
Further, if this is happening for all your parts, I would bet that Automatically Update is turned off in the template file.
Boy, do I feel stupid. The tech support guy at my reseller also was stumped. Thanks, dude.
@12GAGE your issue appears to be with mass calculated on sub-assemblies? Are you working with assembly level features and do you IPA into the subs?
Nominus38's issue was specifically with mass on the individual part files not being correctly set. Although the end results (incorrect mass) are the same, the paths to get there are different.