I'm not new to 3D modelling, in fact have been doing it for games and films for over 10 years. When exporting an OBJ from 3DS Max I can see
the scale is correct, for example a belt buckle at 120 mm in height. When uploading to my Shapeways it all gets a bit confusing with H, W and D
and I can't tell if I have the right scale. Any tips on Units setup from Max to Shapeways?
Also wouldn't it be beneficial for us to scale once we upload as a kind of aspect ratio type in system? that way we don't have to charge more for the
model if it is the wrong scale.
Your best bet is to grab a copy of NetFabb Studio Basic. You'll be able to check all your measurements, wall thicknesses etc and re-scale your models before uploading.
One reason that models don't have any scaling feature here on Shapeways is that when scaled down, there maybe areas of the model that make the model unprintable. Although the suggestion does crop up from time to time it is logical that the model size should be as intended at upload time.