topic Re: Assign mass to a component in Fusion Support Forum

Assign mass to a component

p_riggs — Tue, 15 Apr 2025 08:28:23 GMT

I've seen a few people ask if it's possible to assign a mass (and centre of gravity) to a component, overriding its calculated properties, and the answer always seems to be 'no, use a custom material and calculate its density to give your component the right mass'.

This seems like an awkward hack to provide a very simple feature. The use case is something like this:

I'm modelling some existing component, and I want to create a simple placeholder for it, with the correct mass. I know the mass, I know the external dimensions, this could be a straightforward task. But the workaround requires that I do some calculations to get the density right, and then hope that the CoG is in the right place, because if it's not, I have to modify my placeholder design to hack that too, and then recalculate density. Then if I modify my placeholder, I must go through the process again because changing the geometry changes the mass.

Can I bump this as a feature request? Thanks.

Re: Assign mass to a component

jhackney1972 — Tue, 15 Apr 2025 14:37:36 GMT

Your suggested change to the Fusion application will probably never happen because of liability concerns. If you create a artificial mass and center of gravity for a model and down the road someone uses them for say a lifting point and rigging. When the lift is executed the load swings wildly due to a miss calculation of the center of gravity and the rigging breaks hurting someone, then You can expect to be sued for negligence. Autodesk is not going to add a feature that would allow anyone to make the same mistake as they would then be subject to being sued.

Re: Assign mass to a component

TrippyLighting — Wed, 16 Apr 2025 11:41:21 GMT

@jhackney1972 wrote:

Your suggested change to the Fusion application will probably never happen because of liability concerns.

This can be done in other CAD applications!

Re: Assign mass to a component

TheCADWhisperer — Wed, 16 Apr 2025 12:34:43 GMT

@jhackney1972 wrote:
Your suggested change to the Fusion application will probably never happen because of liability concerns.

Can do it in Autodesk Inventor Professional.

Pretty standard practice - for example, you get a sub-assembly valve from a vendor that is just a shell of the geometry rather than the complete geometry. Override the mass so that when used in your assembly has correct properties.

A variation of this question came up on the Inventor forum this morning...

https://forums.autodesk.com/t5/inventor-forum/weight-calculation/td-p/13428740