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Accuracy of weight calculation

Accuracy of weight calculation

Accuracy of weight calculation

(OP)
Hello everyone!

Working with weight calculation on a complex model involving globally deformed shapes I found that both advanced weight management calculation and direct measuring of solids using 'measure bodies' tools return noticeable error that is equal if advanced weight management accuracy is set to 0.99. When I increased advanced weight management accuracy to 0.9999 the error in the results returned by this tool all but disappeared. Obviously, the error of direct measurement remained the same.

So my question is: can we somehow adjust accuracy of 'measure bodies' tool results, or is it hard-coded to be the same as 0.99 for the advanced weight management?

www.cadroad.com

RE: Accuracy of weight calculation

What version of NX are you using and can you provide the part model that you're working with? And how did you determine the 'correct' weight?

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

RE: Accuracy of weight calculation

(OP)
Sorry, forgot to mention - NX8.5. Unfrotunately, I cannot show a model because it is proprietary.

I judged accuracy of calculation via center of mass. At lower accuracy it wandered quite off 0.0 0.0 0.0, that is wrong, because the part was symmetric. When I increased accuracy, the center of mass returned almost exactly to zero. I also knew the mass of underformed bodies, and compared it to the mass of deformed ones and found a discrepancy that should not have been there, becase deformation did not involve change of volume. When I increased accuracy, the discrepancy all but vanished.

All above is related to the advanced weight management because there I have control over accuracy. I wonder if I can similarily control accuracy of the 'measure bodies' tool.

www.cadroad.com

RE: Accuracy of weight calculation

You can control the 'accuracy' of the results from the 'Measure Body' function by going to...

Preferences -> Measurement...

...and setting the desired 'Accuracy Parameter' or 'Tolerances' in the 'Measure Bodies' section of the dialog.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

RE: Accuracy of weight calculation

(OP)
John, thank you very much! I had a nagging feeling that I was missing something.
A note to myself: always look in the bloody preferences first! :)

www.cadroad.com

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