¿How to get global coordinates of feature?

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Simbioz
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Re: ¿How to get global coordinates of feature?

Post by Simbioz »

drmacro wrote: Wed Dec 01, 2021 5:57 pm
Simbioz wrote: Wed Dec 01, 2021 5:05 pm
chrisb wrote: Wed Dec 01, 2021 7:08 am You may consider to model this differently, by attaching things properly.
I am still not familiar with the attachment process or why it would be necessary/convenient to use it in this situation. I am gonna have a look at the wiki.
Your model seems to be developed in a rather haphazard way. This may be the reason you need global coordinates.
chrisb wrote: Wed Dec 01, 2021 7:08 am Besides: If you model in Part workbench, you should not use the PartDesign clones, use Draft clone instead.
Interesting, I read the respective wikis and I found no fundamental reason to use one over the other for my model. Why are you suggesting this?

Thanks
It is typical to recommend to new user to use either Part workbench or Part Design workbench exclusively.

Once the subtleties of each is experienced, then it is advisable to understand the rules required involved when mixing the two.

If you read this wiki page and have a look at the example of creating identical models with each workbench exclusively you may find some insight:
https://wiki.freecadweb.org/Part_and_PartDesign
And I though that my model was so neatly organized! :D
I am trying to master the part workbench exclusively, but I have had the necessity of using the Draft and Part Design too, the first for rotating 3D objects and the latter for a sketch and clone. That being said, what gives you the impression that it is developed in a rather haphazard way? Is it because how items are arranged in the tree view or because how the model looks like or other reason?
I appreciate your time and insight.
Non native English speaker.
drmacro
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Re: ¿How to get global coordinates of feature?

Post by drmacro »

Simbioz wrote: Wed Dec 01, 2021 7:01 pm
I am trying to master the part workbench exclusively, but I have had the necessity of using the Draft and Part Design too, the first for rotating 3D objects and the latter for a sketch and clone. ...
You should not need Draft to rotate objects. Use Transform or Placement.

You should not need Part Design to sketch and clone.

Simply switch to the Sketcher workbench, create a sketch, sketch the desired shape. Then Part workbench Extrude to create the solid.

Them you can Part Copy or Draft Clone.
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
chrisb
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Re: ¿How to get global coordinates of feature?

Post by chrisb »

Simbioz wrote: Wed Dec 01, 2021 5:05 pm
chrisb wrote: Wed Dec 01, 2021 7:08 am Besides: If you model in Part workbench, you should not use the PartDesign clones, use Draft clone instead.
Interesting, I read the respective wikis and I found no fundamental reason to use one over the other for my model. Why are you suggesting this?
The basic reason is: Modeling is not at all trivial, so you should make your model as simple as possible. The way you cloned has the following disadvantages:

- you don't see on first sight that there is a clone
- you add complexity; there are now two possibilities to position the clone, two possibilities to make it visible
- you add besides the clone itself 8 elements to the tree (3 axes, 3 planes, origin and body)
- you sort of pretend using PartDesign with its different workflow, while in fact using none of these.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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Simbioz
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Re: ¿How to get global coordinates of feature?

Post by Simbioz »

chrisb wrote: Wed Dec 01, 2021 7:08 am You may consider to model this differently, by attaching things properly.
I read the part attachment wiki.
To summarize, this model is comprised of different parts and I want the whole model to be as parametric as possible, by that I mean modifying an object placement or dimension will likely alter the placement or dimension of many other objects located in different parts. So I am not using the transform option. At present, I am trying to bound the Y coordinate of an object in a part to the Y coordinate of another object in a different part (in this case of a vertex of the other object). I have been using the placement property (declaring dimensions and positions as expressions) and a spreadsheet. This has worked mainly for objects in the same part, I guess because they share the same origin. But now I want to tie the placement of objects with different origin, and I am having trouble calculating the offset as an expression between these origins. That's why I asked about how to state the placement of an object in relation to the global origin as an expression.
Now to the attachment part.
I select the object (cylinder004) I want to attach to box005's vertex3, and attach to it with the translate origin mode; supposedly -IIUC- it aligns cylinder004 origin to box005's one. However after attachment the origins do not match and I still have the same issue.
Any insight into how to resolve this problem is greatly appreciated, ideally without to recourse to any python code.
Thanks, and thanks for your patience.
Non native English speaker.
chrisb
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Re: ¿How to get global coordinates of feature?

Post by chrisb »

Simbioz wrote: Thu Dec 02, 2021 9:51 pm I select the object (cylinder004) I want to attach to box005's vertex3, and attach to it with the translate origin mode; supposedly -IIUC- it aligns cylinder004 origin to box005's one. However after attachment the origins do not match and I still have the same issue.
Any insight into how to resolve this problem is greatly appreciated, ideally without to recourse to any python code.
This is difficult to discuss on a purely textual basis. You may have a look at the Basic Attachment Tutorial.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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Simbioz
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Re: ¿How to get global coordinates of feature?

Post by Simbioz »

chrisb wrote: Fri Dec 03, 2021 12:59 am
Simbioz wrote: Thu Dec 02, 2021 9:51 pm I select the object (cylinder004) I want to attach to box005's vertex3, and attach to it with the translate origin mode; supposedly -IIUC- it aligns cylinder004 origin to box005's one. However after attachment the origins do not match and I still have the same issue.
Any insight into how to resolve this problem is greatly appreciated, ideally without to recourse to any python code.
This is difficult to discuss on a purely textual basis. You may have a look at the Basic Attachment Tutorial.
Will do, thanks.
Non native English speaker.
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