PartDesign Chamfer issue

[Satorus]

Dear all,

I thought long time about posting this or not but I cannot figure it out by my own and this topic really drives me crazy.
I often have the case, that I need to add chamfers and fillets to my parts.

I run into issues with these commands very often in FreeCAD so I made a simple example of what really I cannot understand.

Imagine creating a 10x10x10 block and trying to have three edges of this block chamfered. I would assume that there is geometrically no issue in doing this. But when selecting the edges in FreeCAD it gives me an error.

So I have played around and tried to add chamfers in two edges first and the second afterwards but this also gave me no success. But I COULD add a second Sketch and subtract the third edge from the part without an issue. This does not work on complex parts, shapes and splines.

The only way I found out to make it work in FreeCAD is when the first and second chamfers are created in different features and with a 0,001mm difference. Than the third chamfer is possible to be created with default dimension again…
I somehow have the feeling that there is a issue with the chamfer command.

Chamfer-FreeCAD.png (47.38 KiB) Viewed 875 times

To double check I have also tried the chamfer command in other CAD software and you can see the results in the screenshots.
Left cube is when selecting all edges in one chamfer command and right is when selecting edge by edge.

So anyone knows what’s going on with the FreeCAD chamfer command? Why is it not working as expected and is there anyone of you having a solution for that?

Thank you in advance guys.

Chamfer-NX.png (11.99 KiB) Viewed 875 times

Chamfer-Catia.png (28.78 KiB) Viewed 875 times

OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24291 (Git)
Build type: Release
Branch: releases/FreeCAD-0-19
Hash: 7b5e18a0759de778b74d3a5c17eba9cb815035ac
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.0
Locale: German/Germany (de_DE)

[drmacro]

Chamfers and fillets are a problem when more than 2 edges are involved. (Well actually in a lot of other cases as well... )

It's mostly an issue with the OpenCASCADE modeling kernel and FreeCAD can do little to improve it.

It is best to incorporate chamfers and fillets in the sketch when possible.

[NewJoker]

It is best to incorporate chamfers and fillets in the sketch when possible.

Even more a pity that there's no chamfer tool in the Sketcher and chamfers have to be drawn manually.

[drmacro]

It is best to incorporate chamfers and fillets in the sketch when possible.

Even more a pity that there's no chamfer tool in the Sketcher and chamfers have to be drawn manually.

I suspect you will love the new tools that are being worked on then.

But, if you need it that much, a macro/Python should be doable. (I believe I've seen one or more lurking around...)

I don't find drawing a line across a corner and using the trim tool too onerous a task...

[Shalmeneser]

In my 0.20 version :
Fillets :
* 1+1+1 : OK
* 2+1 : OK
* 1+2 : FAIL
* 3 : OK (triangle)
* All : OK (triangle)

Code: Select all

OS: Windows 10 (10.0)
Word size of FreeCAD: 64-bit
Version: 0.20.28929 (Git)
Build type: Release
Branch: master
Hash: 9251480ddb
Python 3.8.13, Qt 5.12.9, Coin 4.0.0, OCC 7.5.3
Locale: French/France (fr_FR)
Installed mods: 
  * fasteners 0.3.41
  * Manipulator 1.4.3
  * sheetmetal 0.2.49

[NewJoker]

I suspect you will love the new tools that are being worked on then.

Definitely, I can't wait to see paddle's work implemented.

But, if you need it that much, a macro/Python should be doable. (I believe I've seen one or more lurking around...)

Another workaround that some people choose is to use the Sketcher CreateFillet tool, turn it into construction geometry and connect the points with a line to create a chamfer.

[drmacro]

...

I almost always use the polyline tool and just include the chamfers as I go.

And, I keep the sketch as simple as possible, opting for additional sketches, opposed to fewer more complicated sketches.

[Satorus]

In my 0.20 version :
Fillets :
* 1+1+1 : OK
* 2+1 : OK

I have downloaded and tried newer versions of FreeCAD now and it seems that with a higher OCC version the chamfer and fillet command is getting better and better.

Now with the FreeCAD 0.20 Version I have managed to get awesome results! Thank you very much for the hint!!

Have a great day to you all

Code: Select all

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.28968 (Git)
Build type: Release
Branch: master
Hash: 03f38526172d8bc6274ddfb5cdd3ad6b691f5f56
Python 3.8.10, Qt 5.15.2, Coin 4.0.1, OCC 7.6.2
Locale: German/Germany (de_DE)

[adrianinsaval]

I had no issue creating the 3 at the same time or one at a time either so it seems this was fixed in occ

Code: Select all

OS: KDE Flatpak runtime (KDE/plasma)
Word size of FreeCAD: 64-bit
Version: 0.20.28936 (Git)
Build type: Release
Branch: (HEAD detached at 0.20beta1)
Hash: b02705d79f2e1adc7773f0c845e0acc5ae8fde4b
Python 3.9.9, Qt 5.15.4, Coin 4.0.0, OCC 7.6.2
Locale: English/United Kingdom (en_GB)
Installed mods: 
  * CfdOF 1.16.7
  * AirPlaneDesign 0.4.0

[drmacro]

...

I'm using 0.20 with OCCT 7.7, and yes it is getting better.

But, I still stand by my comments and recommendations.