Messy sketch after changing external references ?

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JPL
Posts: 10
Joined: Wed Mar 22, 2017 10:37 pm

Messy sketch after changing external references ?

Post by JPL »

Hello there,

I swear that I did a set of fine sketches with a L-shape base ("socle" in french) with sides along each edge, with a central pad with a fall. It was looking good (thanks for NormandC who gave me some tips).

Trying to make it even better, I wanted to add on the base some extra areas to put holes for screws. I did use the trim edge tool, construction lines, circles attached to lines, etc.

The result was really appealing, even if sometime I did experience some application crashes :oops: .

After good efforts, I went back to my "edge" sketch and then had the (awfully bad :twisted: ) surprise to see it upside down, as you can see below :

[img]
Screen Shot 2017-03-25 at 17.41.25.png
Screen Shot 2017-03-25 at 17.41.25.png (51.98 KiB) Viewed 809 times
[/img]

When shown together, the external references seems to cause the problem because they were changed in an earlier part.

[img]
Screen Shot 2017-03-25 at 17.41.25.png
Screen Shot 2017-03-25 at 17.41.25.png (51.98 KiB) Viewed 809 times
[/img]


Is there a way to recover ?

Should I redo the model, is there something that I did wrong and should avoid to get this mess again ?


Thanks for all,




Jean-Philippe

OS: Mac OS X
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6706 (Git)
Build type: Release
Branch: tag: 0.16.6706
Hash: f86a4e411ff7848dea98d7242f43b7774bee8fa0
Python version: 2.7.11
Qt version: 4.8.7
Coin version: 3.1.3
OCC version: 6.8.0.oce-0.17
Attachments
Base v7a.FCStd
(45.3 KiB) Downloaded 32 times
Screen Shot 2017-03-25 at 17.54.26.png
Screen Shot 2017-03-25 at 17.54.26.png (100.73 KiB) Viewed 809 times
chrisb
Veteran
Posts: 53933
Joined: Tue Mar 17, 2015 9:14 am

Re: Messy sketch after changing external references ?

Post by chrisb »

If you change things in an underlying sketch in a way that you create new edges or faces you are most likely to break your model. It is the so called topologica naming problem. You may search the forum for more information, e.g. here: https://forum.freecadweb.org/viewtopic. ... 14#p155014.
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