How to delete detail of this step file

[run_the_race]

So the official raspberry pi step file is 65Mbs. Someone simplified it to a 6.5MB file, which you can get here:
https://github.com/aep/kicad/raw/master ... m-min.step

I am trying to further simplify it as my computer struggles with it when used in another project. I think it is because of all the little round balls under the "BROADCOM_BCM2711" and the `SAMSUNG_KLM4G1YE4C-B00X` items in the tree, like this:

1_balls.png (127.75 KiB) Viewed 990 times

I have tried two methods and neither is successful:
1. Create a box in the `Part` workbench, position it with the Draft move (with snap enabled). Then perform a boolean cut:

2_cube.png (87.23 KiB) Viewed 990 times

It creates a `cut` object. I then delete the original item (because I am trying to reduce the filesize/complexity), but then everything breaks. I try to export it as a step file and then FreeCAD closes.

2. I found an icon that "Explode Compound". This seemed perfect in that I could then select the "BROADCOM_BCM2711", explode it, then try delete the sub parts which are the balls. However "Explode Compound" once again makes a ouput that is dependent on the original. I just don't seem to be able to delete something so it can be simple without creating a more complex version.

What is the correct work flow to trim a step file?

Code: Select all

OS: Windows 10 Version 2004
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24276 (Git)
Build type: Release
Branch: releases/FreeCAD-0-19
Hash: a88db11e0a908f6e38f92bfc5187b13ebe470438
Python version: 3.8.6+
Qt version: 5.15.1
Coin version: 4.0.1
OCC version: 7.5.0
Locale: English/United Kingdom (en_GB)

[drmacro]

Just select the things in the tree you want to delete and hit the delete key.

[run_the_race]

Just select the things in the tree you want to delete and hit the delete key.

I would like to keep the chips, because they are required for heatsink design, I only want to delete the little balls, that are part of the compound chip object, each ball is not individually listed in the tree.

[drmacro]

Expand the subfolder. Are the balls separate objects? Then select them and delete.

Otherwise, maybe draw a plane and use slice apart then delete the one of the resulting slices?

Sorry, the STEP file I have of a Pi doesn't use have the BGA, so I can't try it.

[UR_]

Applv an appropriate view for selecting all balls, using menu Edit->

Screenshot 003.png (7.5 KiB) Viewed 928 times

Forward selection to PartWB->Defeaturing

Screenshot 002.png (6.82 KiB) Viewed 928 times

Be warned: Heavy cpu torture will follow!

[Chris_G]

It creates a `cut` object. I then delete the original item (because I am trying to reduce the filesize/complexity), but then everything breaks. I try to export it as a step file and then FreeCAD closes.

Part Boolean Operations are parametric objects. If you delete one of its source objects, it will break.
You must create a simple copy of the cut object (Part menu -> create a copy -> create simple copy)
Then you can delete the Cut, Box and BROADCOM_BCM2711 objects.

[drmacro]

I have removed BGA's and replaced them with simple extrusions...the resulting FC file is still just under the size limit for the forum.

Snip macro screenshot-8a4ff6.png (95.74 KiB) Viewed 875 times

[run_the_race]

Applv an appropriate view for selecting all balls, using menu Edit->

Forward selection to PartWB->Defeaturing

Be warned: Heavy cpu torture will follow!

Thank you for this, I was very hopeful, It sounds like the right workflow... CPU torture indeed! CPU at 100% for hours, eventually left it over night, in the morning FreeCAD had crashed Did it work for you?
Seems unproportional the amount of CPU power required to delete some features.

[run_the_race]

I have removed BGA's and replaced them with simple extrusions...the resulting FC file is still just under the size limit for the forum.

Wow thank you so much! Well done! How did you do it? It looks like you drew a box and made a union over the balls? Then somehow simplified the resultant object to get rid of the ball references?

[easyw-fc]

simply do a common with a box

cm-min-model.FCStd

(534.03 KiB) Downloaded 33 times