Freecad Idomatic Method for Radial Cylindrical Cutouts

[Shalmeneser]

Do not look at Placement, but Attachment.

[Roland]

How about this solution?

It's the same as Willem's solution made with Part workbench.

It is not the same, Chris.
And I am afraid that Willem's solution is incorrect. See my remark somewhere lower in this thread as a response to Willem.

Greetz

Roland

[Roland]

Do not look at Placement, but Attachment.

Well, that Attachment is wrong as it intersects with the origin!

Screenshot from 2021-08-02 01-02-06.png (18.98 KiB) Viewed 1082 times

So, I agree with you: we need a datumplane. At least one.

And if you want to use the Groove feature, you need also to find the axis around which to sweep the sketch, and that axis is NOT the Z axis of this model.
.
Perhaps this illustration helps to better grasp the matter:

Screenshot from 2021-08-02 01-16-48.png (35.58 KiB) Viewed 1059 times

See also the comment by Papyblaise.

I am trying some more potential solutions inside Part Design. So far I could only manage with a combination of Part Design ad Part.

Happy modelling!

Roland

[Shalmeneser]

Sketch002 : Support : DatumPlane(000)
DatumPlane(000) :
* Support : YZ_Plane
* Attachment : Y angle = 45°

[TheMarkster]

Could be there are better or more efficient ways to do it.

Markster, I think that your solution is wrong because what should have been a circular cylindrical surface is actually an elliptical cyclinder. This is because you sweep a circle along an angled direction.

Best regards,

Roland

I see what you mean. Yes, it is not a circle.

Snip macro screenshot-1cab3e.png (53.73 KiB) Viewed 1047 times

Edit: but looking at the original picture it appears it could be elliptical. It is hard to say from the image.

[GeneFC]

I see what you mean. Yes, it is not a circle.

Seems like that is very easy to remedy. Just make two profile sketches at the correct angles instead of trying to make do with one in the middle.

Gene

[TheMarkster]

I see what you mean. Yes, it is not a circle.

Seems like that is very easy to remedy. Just make two profile sketches at the correct angles instead of trying to make do with one in the middle.

Gene

Yes, that would be the way to do it, assuming you want circles for those faces. I'm not yet convinced that is what the original is depicting.

[hpbmo]

Hi

Do you think I got it?

flange_hpb.jpg (28.29 KiB) Viewed 987 times

hpb

OS: Windows 10 (10.0)
Word size of FreeCAD: 64-bit
Version: 0.20.25334 (Git)
Build type: Release
Branch: master
Hash: 433c52c290681992346b6cda6482bf6a73d74e25
Python version: 3.8.10
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: German/Switzerland (de_CH)

[papyblaise]

If someone can do without the Datum plane ...

See the solution of hpbmo
I was going to offer you another one, but it's useless, it's up to you to invent one

[chrisb]

Do you think I got it?

Almost. Fillets which consume the whole adjacent face and touch the thext edge frequently fail. So I'm afraid this solution works just here.