Adding Up Part Parameters in an Assembly

[spost1]

I'm working on an assembly that must meet the requirements of ANSI/AIAA S-120A for tracking total system weight including contingency factors based on the part type and design maturity. For example, if we have just a standard structural piece of aluminum that Creo estimates to be 1.0 lbm, we need to tack on a contingency factor of 8%. So the part's nominal mass would be 1.0 lbm and it's max mass would be 1.08 lbm. I've been able to account for this so far using a "CONTINGENCY_FACTOR" parameter in my parts and a relation defining "MASS_MAX" as

MASS_MAX = PRO_MP_MASS * (1 + CONTINGENCY_FACTOR)

.So far so good.

My problem comes in at the assembly level. How can I add up all of the MASS_MAX values from all of the parts in an assembly for use in (ideally) both the model tree and the mass properties report?

[BenLoosli]

Instead of using a relation/parameter, try using an alt mass prop value and see if those will propagate to your assembly.

[spost1]

Great thought! But unfortunately it doesn't look it sums the alternate mass at the assembly level.

[MartinHanak]

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@spost1 wrote:

I'm working on an assembly that must meet the requirements of ANSI/AIAA S-120A for tracking total system weight including contingency factors based on the part type and design maturity. For example, if we have just a standard structural piece of aluminum that Creo estimates to be 1.0 lbm, we need to tack on a contingency factor of 8%. So the part's nominal mass would be 1.0 lbm and it's max mass would be 1.08 lbm. I've been able to account for this so far using a "CONTINGENCY_FACTOR" parameter in my parts and a relation defining "MASS_MAX" as

MASS_MAX = PRO_MP_MASS * (1 + CONTINGENCY_FACTOR)

.So far so good.

My problem comes in at the assembly level. How can I add up all of the MASS_MAX values from all of the parts in an assembly for use in (ideally) both the model tree and the mass properties report?

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Hi,

I think you are able to show MASS_MAX part parameter in assembly model tree

Workaround no.1

Save model tree contents into text file, load the file into Excel and calculate the sum.

Workaround no.2

Create drawing with repeat region table containing 2 columns (asm.mbr.name, asm.mbr.MASS_MAX).

Calculate the sum using information from https://www.ptc.com/en/support/article?n=CS25581

1.Table > Repeat Region
2.Select Summation under TBL REGIONS > select the region > Add > By Name > select the parameter name
3.Enter the parameter name > Pick a table cell where summation is to be placed > Done/Return > Update Tables > Done

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See screenshot of my drawing table.

[SYNDAKIT]

This is a bit messy but this might work.

/*========================================================
/* [~ PART LEVEL WEIGHT ~]
/*========================================================
CONTINGENCY_FACTOR=.08
MATERIAL_DENSITY = .2833
MASS_MAX = (MATERIAL_DENSITY * PRO_MP_VOLUME) * (1 + CONTINGENCY_FACTOR)
MP_DENSITY = MASS_MAX / PRO_MP_VOLUME
/*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^





/*========================================================
/* [~ ASSEMBLY LEVEL ~]
/*========================================================
ASM_WEIGHT = PRO_MP_MASS
/*^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[Chris3 · Accepted solution]

I am going to suggest that you are going about this the wrong way. Those contingency factors change as the design evolves. I would suggest instead that you dump the mass properties into a spreadsheet and then handle this in the spreadsheet. This is what we do. Otherwise any time a factor changes you have to go in and change a bunch of parts and or relations.