Stl export error and pocket error

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AndrewCSP
Posts: 16
Joined: Sun Jun 02, 2019 8:02 pm

Stl export error and pocket error

Postby AndrewCSP » Sat Aug 17, 2019 5:23 pm

I have a fairly simple design made in Part Design workbench. The last command was to create a through hole and chamfer it. The result looks correct in the 3D view, but the pocket (labelled Hole) has an error symbol on it which I can't get rid of. I have tried to chamfer in both Part Design workbench and Part workbench, but neither solves the problem.
When I export to Stl file, the hole and chamfer disappear. I get the same problem on both Mac and Windows.
Mask8mm FCStd file.png
Mask8mm FCStd file.png (70.14 KiB) Viewed 264 times
Mask8mm stl file.png
Mask8mm stl file.png (47.21 KiB) Viewed 264 times
OS: macOS 10.14
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16117 (Git)
Build type: Release
Branch: (HEAD detached at 0.18.2)
Hash: dbb4cc6415bac848a294f03b80f65e888d531742
Python version: 3.6.7
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedKingdom (en_GB)
Attachments
Mask8mm.FCStd
(24.57 KiB) Downloaded 5 times
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bejant
Posts: 5809
Joined: Thu Jul 11, 2013 3:06 pm

Re: Stl export error and pocket error

Postby bejant » Sat Aug 17, 2019 6:33 pm

I don't get the error symbol when I open your file, nor after a Force Recompute, but the Report View does read:
Part::Chamfer / Chamfer: Links go out of the allowed scope

I'd delete Chamfer, then use a Part Design WB > Chamfer (not Part WB> Chamfer).

OS: Ubuntu 18.04.2 LTS
Word size of OS: 32-bit
Word size of FreeCAD: 32-bit
Version: 0.18.1.
Build type: Release
Python version: 3.6.7
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)
AndrewCSP
Posts: 16
Joined: Sun Jun 02, 2019 8:02 pm

Re: Stl export error and pocket error

Postby AndrewCSP » Sat Aug 17, 2019 8:33 pm

Thanks bejant. I now can't see the Error box that was appearing any more. There does seem to be a small white down-pointing arrow on a green background superimposed on the chamfer symbol. I have deleted the chamfer and tried with the Part Design WB but the effect is the same - same symbol and same looking result. The problem is the export to Stl, because that is the file I will use to 3D print. The hole and chamfer just don't appear in the Stl file. (I export to Stl format, then open the Stl file in FreeCAD to review it.)

Andrew
openBrain
Posts: 1827
Joined: Fri Nov 09, 2018 5:38 pm

Re: Stl export error and pocket error

Postby openBrain » Sat Aug 17, 2019 8:43 pm

There are 2 common traps when exporting to STL.
The first is that when using PartDesign, you have to select the last Body operation only before exporting. You should not select the Body itself, or use commands like "box selection".
The second is to choose the right format. There are several STL formats in the list. "FEM mesh" shall not be used (can't remember the name of the correct one).
AndrewCSP
Posts: 16
Joined: Sun Jun 02, 2019 8:02 pm

Re: Stl export error and pocket error

Postby AndrewCSP » Sat Aug 17, 2019 11:06 pm

Thanks OpenBrain. You are spot on.

I was using CTRL-A to select everything before exporting, whereas I should have only been exporting the visible parts (typically the last line of the tree). So any error of the pocket was not the problem.
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bejant
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Joined: Thu Jul 11, 2013 3:06 pm

Re: Stl export error and pocket error

Postby bejant » Sun Aug 18, 2019 12:10 pm

openBrain wrote:
Sat Aug 17, 2019 8:43 pm
before exporting. You should not select the Body itself,
I've been selecting the Body, which seems to create the desired .stl mesh without voids becoming filled. I just tested a simple example by selecting the last Feature from the history tree, and that worked too.

OS: Ubuntu 18.04.2 LTS
Word size of OS: 32-bit
Word size of FreeCAD: 32-bit
Version: 0.18.1.
Build type: Release
Python version: 3.6.7
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)
kisolre
Posts: 1249
Joined: Wed Nov 21, 2018 1:13 pm

Re: Stl export error and pocket error

Postby kisolre » Sun Aug 18, 2019 1:53 pm

Selecting Body should export the "Tip" feature, not the "Last" one. 99% they are the same but not always.
openBrain
Posts: 1827
Joined: Fri Nov 09, 2018 5:38 pm

Re: Stl export error and pocket error

Postby openBrain » Sun Aug 18, 2019 2:51 pm

bejant wrote:
Sun Aug 18, 2019 12:10 pm
I've been selecting the Body, which seems to create the desired .stl mesh without voids becoming filled. I just tested a simple example by selecting the last Feature from the history tree, and that worked too.
kisolre guessed right why I generally advise as is. I also guess (didn't really test actually) that selecting Body exports Tip. ;)
For very most people it shall do what is expected, but hitting target at 100% is IMO a better thing.
Also this way you can export any "state" of a PartDesign model very simply. :)
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papyblaise
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Location: France

Re: Stl export error and pocket error

Postby papyblaise » Sun Aug 18, 2019 3:01 pm

Hello
they are several mistake in your file
the best way is constraint 100% the sketch and erase all bleue line off construction
you facing the circle on the top face , and trai to use the tool "Hole , the probleme is that hole start from the face where is facing , and when you use "cunthersink you have to enter a big diameter and the consequence is : you milling the side of the form too
the best way is facing the circle on the base
or use "Pad and "chamfer
as Openbrain , they are 2 formats to export , the right one is : "STL Mesh"
last point if you draw 100% in Partdesign , you select "Body to export
Attachments
mask8.stl
(16 KiB) Downloaded 2 times
mask8.PNG
mask8.PNG (17.54 KiB) Viewed 175 times
mask8.FCStd
(30.35 KiB) Downloaded 4 times
AndrewCSP
Posts: 16
Joined: Sun Jun 02, 2019 8:02 pm

Re: Stl export error and pocket error

Postby AndrewCSP » Sun Aug 18, 2019 7:14 pm

papyblaise,

Thank you very much for your pointers, and for returning a completed file. I hadn't thought of removing the construction lines, so that's a great tip.
I didn't expect it would make any difference which side (top or bottom) I started the hole from. I want the 45 degree face around the hole, and I made the chamfer 2.9mm because the base thickness is 3mm. Its not a hole for a screw head!
In another object I designed, there was additional text and some guard rails on the object, so the design was more than a single body. In that I had to select more than the body to create the Stl file, so that was where I learnt to drag select everything in the tree. I have learnt my lesson!
Thanks again for your valuable assistance.