Question about metric units used (mmKs v.s. mmNs)

I was wondering if there was any reason to prefer one of these to
systems of units over the other. I notice that the "mmNs" setting
calculates mass properties in metric tonnes (which doesn't seem
convenient for designing parts smaller than, say, a bread truck). Yet
it seems that this setting is more popular than the "mmKs".

Is there a good reason for using "mmNs" instead of mmKs?

-Dave Adams-

 

How about cgs (centimeter/gram/second) as a unit for smaller parts!?! One
advantage I've noticed is that cc (cubic centimeter) equals gram or the specific
gravity equivalent. One cc of water = 1 gram whereas one cc of steel equals its
specific gravity in grams (being about 7.8). Another is that small plastic parts
might be reasonably measured in grams but hardly ever in Kilos, Tonnes or
Milligrams: most are either too large or too small to be "convenient" units, i.e.
ones that do not require more numbers in zeros than integers which itself requires
some kind of translation. The trick to Pro/e and its units is that there are units
set up for your convenience, but no givens. You can easily make up your own, store
it with an name and reuse it at will.

David Janes

 

David:

Thanks for your response. Your suggestion of the CGS system has a lot
of technical merit. However, we are essentially locked into using mm
because thats typically what our customers use. It seems to be a "hot
button" issue for them too.

In our case we do have some small parts, but we do have a number that
are greater than 1 Kg mass, and a number of our assemblies end up being

-Dave Adams-