Merge Sketches is distorting the sketches
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Merge Sketches is distorting the sketches
Hi all,
I have 3 quadrilaterals, each their own sketch. In each sketch, I have both vertical and horizontal constraints fixing the position (or so I thought!) of each of the corner points, such that these points should not ever be moveable. Each quad is somewhere in (X,Y,Z) (ie they dont all just lie on one of the coordinate planes.
I need to combine these 3 sketches, and after selecting them and clicking on 'merge sketches', I get a single sketch, however, 2 of my quads in this new combine sketch are absolutely no where near where they should be now and have randomly moved to a new place. I cannot for the life of me figure out why this is happening. It is imperative in my sketch that these corner points do not move at all.
Any ideas on why this may be happening? Could it be that the corner point's horizontal and vertical position constraints are not being carried over when combined into the new sketch? Also, whenever I seem to make the horizontal position constraint, it only ever seems to be a distance constrained from the y axis, not the x axis. Ideally I just want the absolute position of the points to be fixed; any ideas?
Cheers,
Chris
FreeCAD v 0.19 using the Ubuntu AppImage
I have 3 quadrilaterals, each their own sketch. In each sketch, I have both vertical and horizontal constraints fixing the position (or so I thought!) of each of the corner points, such that these points should not ever be moveable. Each quad is somewhere in (X,Y,Z) (ie they dont all just lie on one of the coordinate planes.
I need to combine these 3 sketches, and after selecting them and clicking on 'merge sketches', I get a single sketch, however, 2 of my quads in this new combine sketch are absolutely no where near where they should be now and have randomly moved to a new place. I cannot for the life of me figure out why this is happening. It is imperative in my sketch that these corner points do not move at all.
Any ideas on why this may be happening? Could it be that the corner point's horizontal and vertical position constraints are not being carried over when combined into the new sketch? Also, whenever I seem to make the horizontal position constraint, it only ever seems to be a distance constrained from the y axis, not the x axis. Ideally I just want the absolute position of the points to be fixed; any ideas?
Cheers,
Chris
FreeCAD v 0.19 using the Ubuntu AppImage
Re: Merge Sketches is distorting the sketches
Hi Domad!
Unfortunately I am not able to do so for IP related reasons
Re: Merge Sketches is distorting the sketches
I'm afraid there is no simple solution to your task. To be sure:
- You have sketches in different planes in 3D space
- the sketches use external references
If you combine these sketches into one, then the shape will be distorted, because they will keep their original references to external geometry.
There are no 3D sketches, which would be required if all sketches should keep their old state.
- You have sketches in different planes in 3D space
- the sketches use external references
If you combine these sketches into one, then the shape will be distorted, because they will keep their original references to external geometry.
There are no 3D sketches, which would be required if all sketches should keep their old state.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: Merge Sketches is distorting the sketches
Hi there Chris,chrisb wrote: ↑Mon Dec 06, 2021 5:00 pm I'm afraid there is no simple solution to your task. To be sure:
- You have sketches in different planes in 3D space
- the sketches use external references
If you combine these sketches into one, then the shape will be distorted, because they will keep their original references to external geometry.
There are no 3D sketches, which would be required if all sketches should keep their old state.
I think perhaps I can show this which may help (I suspect you may have hit the nail on the head)
Of my 3 sketches, 2 distort when merged. Pre-merge, this is the plane associated with those said 2 sketches: Looking at this plane, it is not aligned with the xy plane. For context, I made these sketches after having revolved some CAD around the Z axis, taking a cross sectional slice of said rotated CAD, before making said cross section into a sketch.
The 1 sketch of the trio that doesn't distort when merged has a plane like this that is aligned with the xy plane and did not come about from rotation Is it due to these planes being differently oriented? And if so, is there a work around?
Cheers,
Chris
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Re: Merge Sketches is distorting the sketches
What are you trying to do, exactly? Perhaps there is a better way instead of using merge sketches, which is non-parametric.
Re: Merge Sketches is distorting the sketches
What I am doing in a nutshell is taking a creating a FreeCAD file where I can quickly make changes to some CAD that I'm working on.TheMarkster wrote: ↑Mon Dec 06, 2021 5:27 pm What are you trying to do, exactly? Perhaps there is a better way instead of using merge sketches, which is non-parametric.
Said CAD exists in 3D toroidal space, and is essentially a 2D profile in the centre of the CAD (that can be changed), which is to be swept down to a set of known end faces of said part. By creating sketches for a) the middle cross section, and b) the 2 end cross sections, I had hoped to make life easier for myself. Part of my work will involve creating a circle through both the middle cross section, as well as a point on either end face, such that I will be able to define a surface which will act to shape the top section of the CAD. So far I have a nice sketch for the middle cross section wherein I can easily change the shape of said cross-section in a way suitable for my work. I then intended to link these 2 sketches together such that I could add the aforementioned circle between the middle and end cross sections. I had hoped that by doing so in a sketch I could constrain the end faces to be fixed/unchanging, and instead change the middle cross section and automatically change the circle that connects the 2. I wanted to create said circle through 3 points, which looks like something that FreeCAD can do quite easily, however, each of those points presently sits in their own sketches, hence wanting to create a single sketch.
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Re: Merge Sketches is distorting the sketches
Without the file it's guesswork, but you might be able to create a 4th sketch and use links to external geometry to get the 3 points from the other 3 sketches and create the circle based on those links to external geometry.
Re: Merge Sketches is distorting the sketches
I just want to know how I can make it so that the construction planes (as shown in my above post) are not slanted and are the same as the top one (xy plane). At this point this is what I would like to know, as this seems to be the issue.TheMarkster wrote: ↑Mon Dec 06, 2021 7:36 pm Without the file it's guesswork, but you might be able to create a 4th sketch and use links to external geometry to get the 3 points from the other 3 sketches and create the circle based on those links to external geometry.
Re: Merge Sketches is distorting the sketches
Hi ChrisFC, hello to the Community!
The * .gif shows two of the different ways to be able to align two sketches (but it could be any other object) arranged randomly in 3D space, the first involves the use of the "Alignment" function, the second (applicable in any case) provides the 'use, Wb "Draft, of the transformation tools (movement and rotation) supported by the snaps functions and of the setting of the work plane.
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- alignment.gif (980.33 KiB) Viewed 1561 times