topic Re: Referencing Center of Mass in Fusion Design, Validate & Document Forum

Referencing Center of Mass

PrecisionDesign — Tue, 05 Sep 2017 20:30:29 GMT

I see that you can place a visible center of mass glyph for selected components in a design but F360 doesn't seem to be able to reference this location with any kind of construction geometry or dimensions. It sure would be great to reference this point to balance out designs that require it. I did run across a thread in the scripts/ API section but I could not decipher how to implement the listed script or what it actually did.

http://help.autodesk.com/view/fusion360/ENU/?caas=caas%2Fdiscussion%2Ft5%2FFusion-360-API-and-Scripts%2FCan-the-Fusion-API-call-center-of-mass-information-%2Ftd-p%2F6396655.html

Any thoughts or suggestions?

Thanks Again,

Brandon S.

Re: Referencing Center of Mass

Anonymous — Tue, 05 Sep 2017 21:57:59 GMT

Hi Brandon,

One possible way is to ascertain the cords of the com from the properties dialogue, then construct three offset planes using those coords and then placing a point at the intersection of the 3 planes using the construct point through 3 planes. To reference that point you would need to hide the body first. Clunky??

Regards

John

Re: Referencing Center of Mass

jeff_strater — Tue, 05 Sep 2017 23:15:00 GMT

Yes, @PrecisionDesign, this is correct. Today, that indicator is a visual reference only, unfortunately. It is on our road map to implement a way to reference this in other features.

However, this is not as easy as it might sound at first. For instance, say you project the COM into a sketch, then use that sketch to add material to the design. Now you have changed the COM of the object, so, in one way of looking at it, this is a circular reference. So, some references to COM need to be references at a given point in time. But other references, such as perhaps a fixture that needs to be in the COM for balance, needs to always update to the current geometry of a component.

All of these can be worked out, of course, but will just take some time.

Jeff

Re: Referencing Center of Mass

PrecisionDesign — Wed, 06 Sep 2017 00:28:58 GMT

Jeff,

It is great you are working on this. It is also reassuring that you brought up some important requirments to its functionality. When you are balancing a system the components that are driving the system effect the COM position and as they move to a calculated position the position to balance them also moved.

Thank You,

Brandon S.

Re: Referencing Center of Mass

visserCGWTG — Tue, 15 May 2018 07:58:49 GMT

Also I can not find the accumulated mass of the selected parts thatt amount to the COM. I would expect it to be in the analysis.

Re: Referencing Center of Mass

PrecisionDesign — Tue, 15 May 2018 13:17:10 GMT

To find the total of mass of an assembly the bodies or components to be measured need to reside under a single component assembly. I have had to copy and paste the desired components that I wanted to measure into a seperate file if my design structure had extra components I didn't want into the mass calculation. A good practice is to make sure you turn off the capture design history in the new file to get your mass measurements so that you dont get any reference failures when you paste components into it.

Once you have the the new assembly you want to run mass calculations on right click the top level component assembly that contains your pasted components and select properties, this will give you the information you are looking for assuming you have your component materials applied correctly.

Hope This Helps,

Brandon

Re: Referencing Center of Mass

visserCGWTG — Tue, 15 May 2018 13:38:17 GMT

Hi Brandon,

Thanks for your reply. It helps. It still would be easier if the COM-analysis simply would state the total mass of the selection I think. To determine the COM, it must be a known parameter already I should expect. I noticed that a linked component (OEM-file) consisting of a number of subcomponents already had it's total mass under properties. The main component there is a Nylon grip. One shouldn't forget to change it's material property to that material, since those properties are not imported with the file and Fusion sets it to it's default material 'steel' and that makes a difference off course.

Regards,

Pieter

Re: Referencing Center of Mass

calebtallakson — Sat, 19 Jul 2025 23:47:17 GMT

Hey, Jeff! Has there been any progress on implementing this feature? I am finding even just being able to have a "dead" reference to the COM would be very useful.