Macro to compute center of mass

[schupin]

Hi all,

I just created my first macro for FreeCAD !

It's a small macro to compute the weight of multiple solids and the center of mass of the "assembly".

You have to select one or multiple solids and then you launch the macro.
You'll have a window listing the solids. You can put the density of your material or choose in a huge list of predefined materials (I took the values here)
If you know your densities in another unit system, I used FreeCAD convert system to propose differents units.

exportedFile.png (22.11 KiB) Viewed 1481 times

You can also display where is the center of mass :

Interface.png (131.85 KiB) Viewed 1481 times

You can save the computed information in a csv file :

exportedFile.png (22.11 KiB) Viewed 1481 times

A import button allows you to quickly loaded saved densities (even if it's not a .csv file with the macro, as soon as there is a column named "Density" it will be loaded.)

If anyone want to test or have any suggestion to improve it, here is the file :

Files are here : https://github.com/FreeCAD/FreeCAD-macr ... nformation

PS : the design is from here : planosconciri

[thschrader]

Nice tool!
It is easy to generate a material list.
Can you extend the macro for rebars (=arch-structure object)?

rebars.FCStd

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material_list.JPG (127.04 KiB) Viewed 1362 times

rebar.JPG (227.5 KiB) Viewed 1362 times

[bernd]

why not choose the material out of the FreeCAD materials. They have density too.

[schupin]

Nice tool!
It is easy to generate a material list.
Can you extend the macro for rebars (=arch-structure object)?

I'll look at it. I'never work with arch, but it might be possible

why not choose the material out of the FreeCAD materials. They have density too.

It's my first macro and i didn't dive deeply into freecad API.
It was easier to start with this dictionnary. I guess i will easily change it to freecad's material list.
I'll try it soon

[triplus]

Hi all,

I just created my first macro for FreeCAD !

Congratulations and thanks for sharing.

[schupin]

Can you extend the macro for rebars (=arch-structure object)?

That's done !
I also add some lines to make it work with arrays (and arrays of rebars).
If you know some other structures of this kind, let me know !
(I also have to add the pathArray support)

why not choose the material out of the FreeCAD materials. They have density too.

I now use FreeCAD's material list and editor.
I'm not fully convinced since there is not a lot materials within the freeCAD installation files (except if you work with any kind of steel ).
But it's definitely better when you have already made a database.

I also change the button to icons to save place in the interface.
Here is the new version and the icons

centomass_update.png (159.5 KiB) Viewed 923 times

CentOMassesIcons.zip

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CentOMasses.FCMacro

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[galou_breizh]

It looks like a great macro. Can I put it on the official macro repositories (i.e. do you accept that other people can modify your macro)? What license do you want? I suggest the same as FreeCAD itself.

Thanks,
Gaël

[schupin]

It looks like a great macro. Can I put it on the official macro repositories (i.e. do you accept that other people can modify your macro)? What license do you want? I suggest the same as FreeCAD itself.

I'll be glad you add it in the official repo !

The same licence as FreeCAD is ok for me, but I'm not sure the icons I took are compatible with this licence ? (I took them from freepik) It's on CC 3.0 licence.

[thschrader]

Hi schupin,
macro and export to csv works for rebars.
But there is something wrong with the values (970 gramms total for the stirrups?)
Can you have a look at this? Thanks.

rebar_test.FCStd

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I am running on
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15072 (Git)
Build type: Release
Branch: master
Hash: e517c00d9b3da3d1dbe5d5b0159ac5fa95790a8f
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: German/Germany (de_DE)

rebars_csv.JPG (52.86 KiB) Viewed 856 times

mass_rebars.JPG (24.57 KiB) Viewed 856 times

screen.JPG (154.6 KiB) Viewed 856 times

[schupin]

Hi schupin,
macro and export to csv works for rebars.
But there is something wrong with the values (970 gramms total for the stirrups?)
Can you have a look at this? Thanks.

You're right, It took the volume of only one element of the rebar.
It's corrected !
For your file it gives that :

centoMassRebars.PNG (15.32 KiB) Viewed 847 times

I also corrected the units in the export data sheet (everything was in mm in the previous version)

CentOMasses.FCMacro

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