topic Patterned bodies missing from mass calculation in Fusion Support Forum

Patterned bodies missing from mass calculation

hoogendoorn.eelco — Sat, 23 Dec 2023 08:54:58 GMT

Ive got a model of a simple outrunner here; the magnets and coils use a circular pattern; ive placed those bodies into a group for organisational purposes.

Selecting all components and right-clicking properties, I get the expected mass. If I right click the whole component (or when using it inside another assembly), the mass of all patterned/grouped bodies is missing from the total calculation.

The crux seems to be in the grouping of the bodies; if I move them out of the group, they do show up in the mass calculation consistently. I am failing to see any scenario where this is a feature; and not a bug... but am I missing something?

Re: Patterned bodies missing from mass calculation

g-andresen — Sat, 23 Dec 2023 08:59:14 GMT

Hi,

place them in a component

günther

Re: Patterned bodies missing from mass calculation

hoogendoorn.eelco — Sat, 23 Dec 2023 12:07:30 GMT

Thanks, that does seem to do the trick.

Is there an internal logic to that, or is it just a known hack for working around a bug? Ive got to say basic bugs like this make me a little paranoid that the mass calculations of my 400 component assembly actually make any sense (for sure the inertia calculations are a completely incoherent mess, but thats another bug report I guess)

Re: Patterned bodies missing from mass calculation

g-andresen — Sat, 23 Dec 2023 13:05:12 GMT

Hi,

1. it is not a bug.
2. there is no display of properties for body groups.
3. components can consist of individual bodies or be an assembly with subcomponents.
4. if you save your design and paste it from the datapanel into a new (saved) design, you can see that you can display the "total mass" for "outrunner v8".

It may also help to look at the product documentation to see the difference between bodies and components.

günther

Re: Patterned bodies missing from mass calculation

hoogendoorn.eelco — Sun, 24 Dec 2023 06:39:04 GMT

I think im fairly clear on the distinction between bodies and components. I dont think its the crux here though; its the grouping of the bodies that makes the difference in mass calculation; separate component or not.

So placing bodies in a group 'hides their properties'; and thats a feature, not a bug? But what 'properties' does grouping hide? Not their visual ones; I can still see them. Would grouping them also excluded them from, say, collision simulation, or what not? If this 'hiding some subset of properties by grouping' is indeed a feature, id love to see the documentation that explains a clear intuition behind that.