Failure to pad sketch drawn on a face which has the same shape

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LeoTilson
Posts: 7
Joined: Fri Feb 17, 2017 1:19 am

Failure to pad sketch drawn on a face which has the same shape

Post by LeoTilson »

Forum users, Thank you for considering this. It appears to be an edge-case.

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6706 (Git)
Build type: Release
Branch: releases/FreeCAD-0-16
Hash: f86a4e411ff7848dea98d7242f43b7774bee8fa0
Python version: 2.7.8
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17

but it also appears on other versions of FreeCAD which are available to me, including version 0.17

Submitted as Bug Report here: https://freecadweb.org/tracker/view.php?id=2904


1) Open a new document in Part Design
2) New sketch - a teardrop. This consists of
a) An arc of about 270 degrees centred at the origin
b) A line with a horizontal constraint
c) A line with a vertical constraint
d) Where one of the lines joins the end of the arc include a tangential constraint.
3) Pad the sketch.
4) On the new face draw a second identical sketch. Choose the curved part of the sketch as external geometry.
5) Pad the second sketch

At this point we should have a teardrop twice the height of the first, but the model falls apart. The results of the operation are inconsistent, but, put succinctly, the Teardrop Explodes.
The first teardrop
The first teardrop
FirstPad.jpg (198.54 KiB) Viewed 1313 times
Sketch drawn on top face
Sketch drawn on top face
SketchOnFirstPad.jpg (309.99 KiB) Viewed 1313 times
Result of extruding the second sketch
Result of extruding the second sketch
FirstAndSecondPads.jpg (200.79 KiB) Viewed 1313 times
Leo Tilson
Attachments
LeoTilsonTest2.FCStd
The FSCAD file
(9.28 KiB) Downloaded 22 times
chrisb
Veteran
Posts: 53939
Joined: Tue Mar 17, 2015 9:14 am

Re: Failure to pad sketch drawn on a face which has the same shape

Post by chrisb »

No problem here:
OS: Ubuntu 14.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.10101 (Git)
Build type: None
Branch: master
Hash: 99fa203f323927b0dd027420d4421b577b7420c3
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17
Attachments
teardrop_cb.fcstd
(15.76 KiB) Downloaded 24 times
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cox
Posts: 971
Joined: Wed Nov 26, 2014 11:37 pm

Re: Failure to pad sketch drawn on a face which has the same shape

Post by cox »

Migrating the project file fixes the issue in :

OS: "Arch Linux"
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9790 (Git)
Build type: Release
Branch: master
Hash: 294b2308d660a4aae11e90ec22f96ca56190bcd1
Python version: 2.7.13
Qt version: 4.8.7
Coin version: 3.1.3
OCC version: 6.9.1
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Kunda1
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Joined: Thu Jan 05, 2017 9:03 pm

Re: Failure to pad sketch drawn on a face which has the same shape

Post by Kunda1 »

cox wrote:Migrating the project file fixes the issue
What does this mean?
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sgrogan
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Posts: 6499
Joined: Wed Oct 22, 2014 5:02 pm

Re: Failure to pad sketch drawn on a face which has the same shape

Post by sgrogan »

Kunda1 wrote:What does this mean?
See duplicate thread https://forum.freecadweb.org/viewtopic.php?f=3&t=20721
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cox
Posts: 971
Joined: Wed Nov 26, 2014 11:37 pm

Re: Failure to pad sketch drawn on a face which has the same shape

Post by cox »

Kunda1 wrote:
cox wrote:Migrating the project file fixes the issue
What does this mean?
After opening the file in 0.17 dev the model is corrupted as explained in OP's post. Since this model was made in 0.16 it is possible to use Partdesign:Migrate function to upgrade the model to 0.17. Using this function fixes the model according to OP's expectations.
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