Failed to validate broken face error

[NeilBaker]

I am trying to pocket a face and getting 'Failed to validate broken face'.
I have run the 'validate sketch' options from the sketcher menu which says everything is OK.
Some weeks ago I successfully carried out this operation but managed to loose the files I generated then. I cannot remember my workflow from that time. There have been two FreeCAD updates since my successful program use.
Attached is the FreeCAD and OS information, a dxf of what I am trying to do and screenshots of the verification process.

[openBrain]

Hi NeilBaker, Welcome here,

There are several issues with your model.
First if you want to pocket the sketch in the existing part, it should be in the body, not out of it.

Second there is a "lost" arc in your sketch that you can find by zooming at the point shown by the below picture (green arrow). It is named "9-Arc" in the Elements list.
There are also 2 missing coincidences (purple arrows). But endpoints are so far from each other that tool doesn't see it.
You can find all that problems by clicking on the "Highlight open vertexes" of the sketch validation tool.

After patching this issues, the pocket works correctly.

Third it would be better if your sketch was fully constrained (although this isn't mandatory).

errors.png (42.13 KiB) Viewed 540 times

[openBrain]

And also :

• Sketch001 has been created out of the body. This isn't allowed (although FC is friendly enough to work with it). You should drag it inside the body
• Sketch001 is mapped on a Pad face. This isn't recommended for robustness.

I know it's a tough list and I guess from your file that you're probably a newcomer to the 3D modeling world. So welcome again. My question is to know if you intend in learning & progressing in your 3D modeling skills, or just have a one-shot need.
In the first case, I & others will enjoy providing further explanations / tip / links to documentation & tutorials.

[NeilBaker]

Thank you very much for the incredibly quick and informative reply. I will digest properly the information tomorrow The fact it worked the first time must have been beginner's luck. I am much more familiar with 2D CAD (as you probably guessed). I am using this application to create stl files for details an patterns for models I am building. I can bore you with some details of these projects if you like.

[openBrain]

Thank you very much for the incredibly quick and informative reply. I will digest properly the information tomorrow

You're welcome. Do not hesitate to ask for more detailed explanations if needed.

I am much more familiar with 2D CAD (as you probably guessed).

I didn't guess. But that's a good point. Indeed most 2D skilled people I see here just stuck wondering why FreeCAD doesn't work as AutoCAD (or other). Maybe they think from 2D to 3D is just one more D... But that's 2 different worlds, so better approach 3D modeling as something new/different.
If you want to learn a bit about parametric modeling and especially its mandatory sketching activity, I think chrisb's sketcher tutorial is a nice entry point.

I am using this application to create stl files for details an patterns for models I am building. I can bore you with some details of these projects if you like.

Please do. Community here likes to know what FC is used for.

[NeilBaker]

Thanks for your help. I have successfully 3D printed the part you helped with. I will follow up on the link you sent.

As promised, I have attached some pictures of the prototypes of the locos I am building. They will be 7.25" gauge, ~1/8 scale.
I have done most of the design work in Qcad (which I have used for years) I am using FreeCAD to produce models for 3d printing of details and casting patterns.

Thanks again, much appreciated.

[openBrain]

Thanks for your help. I have successfully 3D printed the part you helped with. I will follow up on the link you sent.

You're welcome, glad you succeed.

As promised, I have attached some pictures of the prototypes of the locos I am building. They will be 7.25" gauge, ~1/8 scale.
I have done most of the design work in Qcad (which I have used for years) I am using FreeCAD to produce models for 3d printing of details and casting patterns.

Hey, I figure out the part you did are the tailpieces on the side of the 1st pic loco.
We hope to see pics of the 3D printed part, and even of the global model. Here or better in the dedicated subforum.

Thanks again, much appreciated.

Believe me, people asking for help here very seldom come back to give fresh news after they solve their problem. You did it ! This is very satisfying for helping forumers, and much much appreciated.

[NeilBaker]

As requested ......