[SOLVED] How to remove a feature in PD without breaking references

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drmacro
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Re: How to remove a feature in PD without breaking references

Post by drmacro »

Mark81 wrote: Wed Aug 03, 2022 11:16 am Great! Last question here, I promise :D
So when it's worth to attach a sketch to a face?
Questions are welcome. ;)

Well, there are some different schools of thought.

One says the workflow of attaching to faces is generally not a good workflow (even if there was no such thing as Topological Naming Problem 'TNP'). Basically it makes for long term maintenance of said model more complicated. Attaching to faces is the lazy (and arguably quick) way to model, but, can be difficult to figure out by others (who may be asked to modify or update the model) or even for the originator when looking at the model down the road. In this workflow, base planes are always the preferred way.

With the current state of TNP, the only time attaching to a face is "worth it" is with very simple/short features trees where fixing isn't too much a bother. Or, for quick-n-dirty models where changes are unlikely. Or, if you understand the ramifications in more complex models and are comfortable fixing the TNP issues when they occur.

Personally, I have just made attaching to base planes my normal "muscle memory" workflow and rarely deal with TNP. (Note: attaching to sketch geometry is less likely to have TNP issues, but, not 100% if, for example, you actually delete geometry or insert arc's in a line, etc.) After you do a few complicated sketch locations, it starts to be pretty straight forward.

There are other possibilities as well, such as sebasg84's Sketch/Plane from face macros https://github.com/sebasg84/planeFromFace
and freedman's TopoX10 https://forum.freecadweb.org/viewtopic. ... 0&start=30
https://github.com/Freedman-CB1/TopoX10

Learning sketch location is a good skill to know long term so I advocate learning the process rather than avoiding it... 8-)
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
Mark81
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Joined: Tue Jul 12, 2022 2:21 pm

Re: [SOLVED] How to remove a feature in PD without breaking references

Post by Mark81 »

Thank you so much for your clear and complete answer!
chrisb
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Re: How to remove a feature in PD without breaking references

Post by chrisb »

Mark81 wrote: Wed Aug 03, 2022 11:16 am So when it's worth to attach a sketch to a face?
Beyond the quick and dirty - which I use myself from time to time and which ends always in rebuilding the model - there are two use cases where there is no loss in stability when attaching a sketch to a face:

1) If you start a body with a primitive such as a cube, then you can safely attach sketches to its faces.

2) If you have an imported object, e.g. from a step file, then nothing is going to change on that object and you can safely attach sketches to its faces. However, if you ever intend to reimport it including changes, this does not hold anymore.
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