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Mass Property Unit

jer3d1
1-Newbie

Mass Property Unit

Hey there,

Is it possible to determine the unit of a mass property using relations?

I can call the mass (or any other mass property) of a part as a parameter to be used in a relation, but I don't seem to be able to find the units.

They are in the reported mass property parameters and they may be identified in a drawing so it makes sense that they would be available, but I have not yet found a way to reach them.

Specifically, I am trying to find the unit for PRO_MP_MASS I.E. - kg, lbm, lbf, g etc.

Thank you,
Jered


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6 REPLIES 6

I don't see anything directly in Pro/Program, or relations, but it is
interesting that when creating tables in drawings, you have the option
of calling out fam.inst.param.unit



This .unit suffix seem to be available for most table reported
parameters in drawings



Now, how to put this in a relation...





Christopher Gosnell

TRIGON INC.
FPD Company
124 Hidden Valley Road
McMurray, PA 15317
PH: 724.941.5540
FX: 724.941.8322
www.fpdinc.com

Ø Is it possible to determine the unit of a mass property using relations?



Well, you can set a unit to a parameter. Relations can combine different parameters with different units of the same 'kind', for example mass. So, if you first create the target parameter with your desired unit of mass, and then create a relation with the option Utilities > Unit sensitive checked (in the Relations dialog). Then you can create relations with parameters that have different units of mass



Ø Specifically, I am trying to find the unit for PRO_MP_MASS I.E. - kg, lbm, lbf, g etc.



In the Parameters dialog, there is a Units column to the far right. If you switch to the Reported Mass Properties view, PRO_MP_MASS will be shown with its current unit system = that of the model itself.



If you your model has a PRO_MP_MASS unit of, say 'tonne' and you wish to have a MASS parameter in the unit 'lbm', just create a parameter 'MASS', set its unit to 'lbm' in the Parameter dialog. Then, in the Relations dialog, set the option 'Utilities > Unit sensitive' and type the relation MASS = PRO_MP_MASS.



If you have the config option mass_property_calculate set to 'automatic', this will keep your PRO_MP_MASS parameter updated on regeneration (and your MASS relation too), at the expense of a little extra regeneration time.



Best regards,

/Petter




dgschaefer
21-Topaz II
(To:jer3d1)

Petter,

I've tried your suggestion for assigning mass to a parameter and using that in relations without success.

My model has standard inlbs units and I'd like to create a parameter that will report the weight in both pounds and grams. I have a WEIGHT parameter that is set via relation equal to pro_mp_mass.

I then created a GRAMS parameter and assigned it the unit 'g'. I selected Utilities > Unit Sensitive in the relations dialog. I then created the relation grams = pro_mp_mass in the post relations section of the relations editor.

However, my GRAMS parameter is reporting the same value as my WEIGHT parameter.

What am I doing wrong?

I'm using WF4, M080

Doug Schaefer

--
Doug Schaefer | Experienced Mechanical Design Engineer
LinkedIn

Hi Doug,

It may be that the Utiliies > Unit Sensitive option is notchecked in the Relations menu. That did the trick in my case.

I attached a sample model to this post (anda screenshot of the Relations setting). I am using WF4 M090 and I have the config setting mass_property_calculate = automatic.

I hope this helps!

/Petter

bfrandsen
6-Contributor
(To:jer3d1)

If you use the Evaluate Expression in the relations editor the reported
parameter value will not be unit converted. But the value shown in the
Tools>Parameters... dialog is correct.

/Bjarne



Petter Frieberg <->
02-09-2009 09:23
Please respond to
Petter Frieberg <->


To
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cc

Subject
[proecad] - RE: Mass Property Unit






Hi Doug,
It may be that the Utiliies > Unit Sensitive option is not checked in the
Relations menu. That did the trick in my case.
I attached a sample model to this post (and a screenshot of the Relations
setting). I am using WF4 M090 and I have the config setting
mass_property_calculate = automatic.
I hope this helps!
/Petter
Chris3
21-Topaz I
(To:jer3d1)

Be careful - if you do edit -> setup -> units and you convert to a new
unit set, it also changes the units in your parameters to match.

Also per the documentation even if it is not checked starting with WF2
by default, relations are unit-sensitive (assuming they have a unit).
Relations created in Pro/ENGINEER Wildfire and previous releases are
evaluated as unitless. After you change relations, they become
unit-sensitive.

All clicking clicking Utilities > Unit Sensitive does is to over ride
the config option relations_units_sensitive no (it's yes by default)

Chris
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