Overriding part and assembly mass

[Ydl]

Hi all,

Did a quick search but found no answers.

Is it possible to override the mass properties of an assembly or part, as can be done in Solidworks?

Follow up question - Is it possible to batch-set all the parts of an assembly to one material?

Thanks.

 

[idslk]

Hi Ydl,

Is it possible to override the mass properties of an assembly or part

from the API Help:
The members of IADPhysicalProperties have "only Get methods...
Public Property Mass Returns the mass of the design.
Public Property Material Returns name of the material used for the design.

Is it possible to batch-set all the parts of an assembly to one material?

from the API Help:
IADDesignProperties. Material Property has a Get and a Set method...

I haven't done this with AlibreScript...
What i've done (this is not very professional, only "quick and dirty"):
Calculate new assembly mass with new density for all parts
This is not tested with high numbers of assembly levels (the number of subassemblies) and could be optimized...
What is your intention to set all parts to one material?

Regards
Stefan

 

[Ydl]

I'm modelling a lot of parts such as Pi's and Arduino modules, with resistors and transistors etc modelled as individual parts (thanks budget keyshot).

I then weigh the part in question, do a bit of basic math with my modelled volume then create a "part material" that I assign to all the parts in the assembly. For something with a few dozen parts, this get old quick.

A quicker alternative is to maybe set zero density material as default (if zero density is possible in Alibre) then just perform this process on say the PCB, but this is less than ideal.

 

[idslk]

Hello Ydl,
OK.
What do you do with the "material"
If it is only for calculation, try the above mentioned script. There you can set the "part material" density very easy to a unreal value...
(It could be extend to print all mass values including part name into an table or something else (as you've programming experience by yourself, it should be no problem...))
If it should be written into the file, i can't imagine for what this could be used in real world. (I thing it could be done from "outside" eg. with python ;-)

Regards
Stefan

 

[Ydl]

Cool script. I might have a look at it in the future, however I’m kind of wanting to save values into my part and assembly files so it doesn’t quite meet my use requirements.

Thanks though.

Doing some of these steps programmatically is always an option - it just kind of gets to the point of “is this something I should need to be doing?”

 

[Lew_Merrick]

Is it possible to override the mass properties of an assembly or part, as can be done in Solidworks?

My question is, "Why would one wish to?" The mass is the volume if the Parts multiplied by their density so that (shall we say) "adjusting their mass involves "adjusting" their density. Inertia's derive from the Part's geometry and it's density. If the geometry and density are correct, so are the Inertia values. ???

 

[Ydl]

My question is, "Why would one wish to?" The mass is the volume if the Parts multiplied by their density so that (shall we say) "adjusting their mass involves "adjusting" their density. Inertia's derive from the Part's geometry and it's density. If the geometry and density are correct, so are the Inertia values. ???

Because Id prefer not to have to model varying fill density/fill type/wall thickness parameters for parts that I'm 3D printing.

Edit: it's also a good feature when you have non-homogeneous materials, such as some foam and laminated products, and modelling individual layers isn't in your time budget, but weights need to be provided on your technical drawings. Not my use case here, but it was in my previous CAD role.

 

[Lew_Merrick]

Edit: it's also a good feature when you have non-homogeneous materials, such as some foam and laminated products, and modelling individual layers isn't in your time budget, but weights need to be provided on your technical drawings. Not my use case here, but it was in my previous CAD role.

Well, I will agree that suppliers of "3D Printing Materials" lie through their teeth about all "properties" they claim (having spent nearly a year-and-a-half performing calibration tests on "3D Printing Materials"). On the other hand, there is "good data" on plastics, laminates, and other "composite" materials. I designed a not-insignificant portion of the Transfer Vehicle" that carried the Curiosity Rover from Earth orbit to the orbit of Mars -- and was accurate on mass within 300 mg and on rotational inertia s to an equal degree.