Changing "lbmass" to "lb."

[josephcooley]

Does anyone else find it odd that the default unit for mass in inventor is lbmass when in actuality it is lb force? The English unit of mass is slugs which I know nobody uses and lb mass is just lb force on earth. I dont think it looks very good to have lbmass after each mass in the parts list.

Does anyone know how to change the default unit from "lbmass" to "lb." also can somebody tell me how to change the accuracy on the mass? I want it to be an approximate weight.



Instead of "123.453 lbmass" I want it to say "120 lb."

[Anonymous]

I thought lbmass WAS lb, it's just called that for whatever reason.

Did you mean to post this here or in the main Inventor forum? If not, were you writing a program or macro and needing the numbers rounded somehow?

[josephcooley]

Well it is and isn't pounds is a force. lbmass is just convenient to use on earth because it is how we think of things. the English unit for mass is a slug. lbmass and lbforce are the same on earth since lbmass is the mass of something on earth represented in lb force. its a stupid unit but it works I just dont like the way it looks although it is technically correct.

Im not trying to get a unit conversion Im just trying to correct syntax.

[Anonymous]

Oh, I'm aware of the difference in the physical world. But inside Inventor, they're kind of the same thing. But if you wanted to use it to design spacecraft, for instance, then you'd probably be using metric units.

How are you wanting to use this unit exactly? If you're trying to correct a macro or add-in for the difference when you output a string, just use some sort of String.Replace from "lbmass" to "lb".

Outside of custom programming, you're just going to have to deal with it being "lbmass". I believe the reason it is this way is because of the way units are classified inside of documents. You have Length, Volume, Area, Time, Angle, Mass, Force, etc. So if you want to deal with pounds as "mass" or weight, it's called "lbmass". But if you wanted pounds as force, it's called "lbforce". Just plain ol' "lb" is too ambiguous.

[Anonymous]

This is something I'd be wondering as well. Since we round up to the nearest 5lbs right now. We'd use the mass field, but would be nice if we could remove lbmass and replace it with lbs.

[mauribailey]

I am so confused about "lbmass" as units...

I know that: weight (the force on an object due to gravity) is measured in pounds "lbs" (the same units used to measure any other force quantity), and that mass (the amount of matter) is measured in "slugs".

Looking at the comment section I see people saying that "lbmass" is the equivalent to weight and therefore could be replaced by pounds "lbs". But looking at the iProperties > Physical tab in Inventor, I see that mass (not weight) is associated with the units "lb mass".

So which is it? Is "lbmass" a force or a mass unit ???