Using construction lines.

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Olav
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Re: Using construction lines.

Post by Olav »

chrisb wrote: Mon Oct 18, 2021 1:23 pm Example for reuse of sketch:
SnipScreenshot-ab5eab.png
This obviously works for a single (physical) hole. I understood the OP wanted two separate pockets, like next to each other.
Olav
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Re: Using construction lines.

Post by Olav »

drmacro wrote: Mon Oct 18, 2021 12:12 pm
Olav wrote: Mon Oct 18, 2021 11:39 am To be clear this is the method I described previously:

https://www.youtube.com/watch?v=vHwngDEy5qI
The method @chrisb describes would (I think) allow a second depth to be specified, amounting to an additional depth for the holes in the sketch.

The method in the video, while it works, is, at this point, almost guaranteed to produce TNP and is thus not recommended workflow.
I had a suspicion that might be the case. Though I think in some cases where perhaps you don't care so much about TNP it can still be handy.

I suppose the conclusion is that no, you SHOULD NOT make separate pockets of different depths from the same sketch.

A more generalised phrasing could be: every feature you create must be based on its own sketch, a single sketch should not try to define multiple features.

Agree, of am I off the mark?
drmacro
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Re: Using construction lines.

Post by drmacro »

Olav wrote: Mon Oct 18, 2021 3:42 pm ...A more generalised phrasing could be: every feature you create must be based on its own sketch, a single sketch should not try to define multiple features.
...
This is an accurate statement for the master branch.

There is some level of being able to select some geometry of a sketch and Pad/Pocket only the selected portion of the sketch in the linkstage3 branch.

IMO, it just adds ways to make the model confusing for long term maintenance.

Also, referring to your comment about "when you don't care about TNP"...IMO, that should approximately never. ;)
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
user1234
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Re: Using construction lines.

Post by user1234 »

drmacro wrote: Mon Oct 18, 2021 3:51 pm
Olav wrote: Mon Oct 18, 2021 3:42 pm ...A more generalised phrasing could be: every feature you create must be based on its own sketch, a single sketch should not try to define multiple features.
...
This is an accurate statement for the master branch.
I absolutely disagree with that. Some features do not need sketches at all. Generally sometimes sketches should be used in multiple features.

Here a minimum example file in a nutshell:
0.FCStd
(31.63 KiB) Downloaded 25 times
0.png
0.png (173.86 KiB) Viewed 1364 times


Greetings
user1234

edit: wording
Olav
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Re: Using construction lines.

Post by Olav »

drmacro wrote: Mon Oct 18, 2021 3:51 pm
Olav wrote: Mon Oct 18, 2021 3:42 pm ...A more generalised phrasing could be: every feature you create must be based on its own sketch, a single sketch should not try to define multiple features.
...
This is an accurate statement for the master branch.
OK. Then I will take that as a general guideline.

There is some level of being able to select some geometry of a sketch and Pad/Pocket only the selected portion of the sketch in the linkstage3 branch.

IMO, it just adds ways to make the model confusing for long term maintenance.
I don't use LinkStage3, I'm strictly concerned with the behaviour of standard FreeCAD.

Also, referring to your comment about "when you don't care about TNP"...IMO, that should approximately never. ;)
Well, if I'm making a quick and simple one-off thing to 3D print or something, I may not be as interested in long term maintenance of my model.
drmacro
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Re: Using construction lines.

Post by drmacro »

user1234 wrote: Mon Oct 18, 2021 4:04 pm I absolutely disagree with that. Some features do not need sketches at all. Generally sometimes sketches should be used in multiple features.

Here a minimum example file in a nutshell:0.FCStd0.png
Speaking of master branch.

Generally a sketch can be used multiple times. A good example is 2 Pad operations in opposite directions. Or a Pad one way and a Pocket the other. As your example shows. (Though I have no idea why you use a Std_Part object...superfluous and extra work in this particular case.)

But, you can't (as yet, AFAIK) select a single edge from a sketch an pocket it. Then select a different edge from the same sketch and Pad it.
Attachments
DoubleTake.gif
DoubleTake.gif (499.66 KiB) Viewed 1301 times
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
user1234
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Re: Using construction lines.

Post by user1234 »

drmacro wrote: Mon Oct 18, 2021 4:52 pm Speaking of master branch.
Of course, me too.


drmacro wrote: Mon Oct 18, 2021 4:52 pm Generally a sketch can be used multiple times. A good example is 2 Pad operations in opposite directions. Or a Pad one way and a Pocket the other. As your example shows.
This is the reason why i wrote, that i disagree with this statement, because it is simply false.


drmacro wrote: Mon Oct 18, 2021 4:52 pm (Though I have no idea why you use a Std_Part object...superfluous and extra work in this particular case.)
Because every Part needs a Std_Part. In the long term, it makes absolutly sense, but maybe not in this file. Call it habit.


drmacro wrote: Mon Oct 18, 2021 4:52 pm But, you can't (as yet, AFAIK) select a single edge from a sketch an pocket it. Then select a different edge from the same sketch and Pad it.
Yes, but this has nothing to do with this statement, every feature you create must be based on its own sketch, a single sketch should not try to define multiple features.


Greetings
user1234
drmacro
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Re: Using construction lines.

Post by drmacro »

user1234 wrote: Mon Oct 18, 2021 5:13 pm ... every feature you create must be based on its own sketch, a single sketch should not try to define multiple features.
I'll give you that this statement casts a wider net than it should.

But, as I showed, i]...a single sketch can not define shapes for multiple features [/i]
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
user1234
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Re: Using construction lines.

Post by user1234 »

With that, i agreed before.

Greetings
user1234
TheMarkster
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Re: Using construction lines.

Post by TheMarkster »

drmacro wrote: Mon Oct 18, 2021 4:52 pm
But, you can't (as yet, AFAIK) select a single edge from a sketch an pocket it. Then select a different edge from the same sketch and Pad it.
https://forum.freecadweb.org/viewtopic.php?f=36&t=62991
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