HELP - Failed to Validate Broken Face - Fully Constrained

[jwhitten]

Hello,

Thanks to everyone who's worked to make FreeCAD such a cool thing!

I'm new to FreeCAD coming from Fusion360. In general, it seems a little different, but similar enough. I've been getting up to speed by making little test parts.

In this example, I am simulating making a machined plate of some sort.

I created a sketch that contains a rectangle, fully-constrained, and inside it, a set of four holes (or rather, eight holes in concentric pairs to make recessed-bolt holes). These holes are constrained by making them coincident with the corner points of a second rectangle drawn from construction lines. Finally, one of the holes is dimensionally-constrained horiz/vert to a point in the outer rectangle, making the whole geometry fully-constrained.

When I go to PAD the sketch, it keeps tossing up a "Failed to Validate Broken Face" error and I can't figure out what I'm doing wrong. All my constraints seem correct. I have the correct number of holes and lines. The sketch validator found no issues. But I keep getting the error. Any idea what I'm doing wrong here?

I've included the test file for your perusal.

(I would also include a screenshot, but I'm not sure how to do that with this forum software.)

Thanks!!

JWhitten

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: English/United States (en_US)

[chrisb]

Hi and welcome to the forum!

You can have at most one nesting level of closed loops. (The innermost circles would create separate solids.)

[GeneFC]

(I would also include a screenshot, but I'm not sure how to do that with this forum software.)

You can use the clipping tool in Windows 10 and then paste the image as an attachment the same way you pasted the FCStd file.

Gene

[Shalmeneser]

For a screenshoot of the 3D view : Std_ViewScreenShot

If all the holes have the same dimensions, it's better to constrain them to be equal : Sketcher_ConstrainEqual.

Try to do the same object in 3 actions (3 sketches, 3 pad/pocket ): rectangle, hole, in the hole.
Perhaps then you'll understand your problem -> multisolids !

One nesting level of closed loops

means the geometry of the pad (=rectangle, level 0) with eventually direct pocket (=holes, level 1).
You try the next level with circles in the holes.

[Bance]

You clearly didn't search this problem because it comes up almost more than any other problem.

Why not!

[ragohix769]

(I would also include a screenshot, but I'm not sure how to do that with this forum software.)

You can use the clipping tool in Windows 10 and then paste the image as an attachment the same way you pasted the FCStd file.

Gene

For me paste images form clipboard doesn't work here in forum; I'm with Linux, but I don't think it's a problem related to the OS (maybe it's the browser?).

[and maybe this https://forum.freecadweb.org/viewtopic.php?t=2956 has to updated/removed]

[jwhitten]

You clearly didn't search this problem because it comes up almost more than any other problem.

Why not!

Actually, I searched it quite a bit. Every answer I saw had something to do with missing lines, incorrect constraints, etc. Nearly all of the answers said to use the Sketch Validator and look through the elements list to find erroneous entries.

I did all of that, and still had the problem. Thus this post.

JWhitten

[jwhitten]

Hi and welcome to the forum!

You can have at most one nesting level of closed loops. (The innermost circles would create separate solids.)

So let me see if I can state/understand this from my F360 perspective-- are you suggesting that I should start with a sketch of the rectangle, then select a face, draw a new sketch on that, and do the holes?

I realize this isn't F360, but if I were doing it there, I would create the sketch (as I described it) then select the faces I want to extrude (pad) and then select the area between the circles and extrude them to create the recessed face for the bolts, and finally, NOT select the innermost holes, which would leave a hole in the part.

I am guessing the major difference here is that FreeCAD won't/(can't?) let me select the "face" area in the sketch?

[jwhitten]

For a screenshoot of the 3D view : Std_ViewScreenShot

If all the holes have the same dimensions, it's better to constrain them to be equal :

Thank you for these tips. I'll remember them for next time.

Try to do the same object in 3 actions (3 sketches, 3 pad/pocket ): rectangle, hole, in the hole. Perhaps then you'll understand your problem -> multisolids !

I think I might understand what you just said-- that I should do one, then select a face, do the next one (another sketch) and so forth ??

[chrisb]

I am guessing the major difference here is that FreeCAD won't/(can't?) let me select the "face" area in the sketch?

Correct. And we had indeed quite some F360 refugees asking for the same. You can well do the holes in the first sketch, but you cannot have a hole of the hole. So remove the innermost circles.