FreeCAD Forum

Hi,
while using the Assembly 4 workbench on FreeCAD 0.19 I encountered the following problem regarding a (master) sketch:

Whenever I leave the first editing session of a sketch the sketch seems to lock
the objects accessible to the "create new coordinate system in part"/"edit
datum" selection dialogue: If I edit the sketch again and add a new vertex or an
edge and then want to attach a coordinate system to it (for instance by entering
'master:Vertex7' in the attached file) I get the error "PositionBySupport:
AttachEngine3D: subshape not found".

I attached a file to demonstrate the issue: master:Vertex7 and master:Vertex8 do
exist (verified via Selection View) but I cannot chose them while attaching an LCS.

This prevents me from adding new reference points in my assembly. Any idea how to resolve this issue? Is it a bug?

OS: Manjaro Linux (XFCE/xfce)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22611 (Git) AppImage
Build type: Release
Branch: master
Hash: 7eeec7a5990cc786723225ca8de16ca3186545b3
Python version: 3.8.5
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United Kingdom (en_GB)

Moved to Assembly forum.

chrisb wrote: ↑Wed Oct 21, 2020 2:32 pm Moved to Assembly forum.

Why ? The user has a problem involving sketches and datum objects, nothing assembly related.

chrisb wrote: ↑Wed Oct 21, 2020 2:32 pm Why ? The user has a problem involving sketches and datum objects, nothing assembly related.

I don't mind where this is discussed, but it seemed well assembly related, because the file contains LCSs which arent created that way by the core application. You may help finding the issue by reproducing it without any such specials.

chrisb wrote: ↑Thu Oct 22, 2020 12:39 am

chrisb wrote: ↑Wed Oct 21, 2020 2:32 pm Why ? The user has a problem involving sketches and datum objects, nothing assembly related.

I don't mind where this is discussed, but it seemed well assembly related, because the file contains LCSs which arent created that way by the core application. You may help finding the issue by reproducing it without any such specials.

Zolko is right: the issue occurs also when using the PartDesign workbench and
seems to be only connected to single points: So far I only added single
points on edges after doing the initial sketch and was wondering why I then
could not select them (Even though they are clearly there and have a name/label
like "Sketch:Vertex9"). In fact it does not matter when or where I add single
points, I never can select them for attachment.

So if I want to attach an LCS on a new vertex positioned on an edge between to other
vertices, I need to delete that edge and redraw as two edges (or polyline).

I don't know if that behaviour is intended due to some limitation but it would
certainly be comfortable to simply add points on lines and have them available
for attaching LCSs. So, would it be reasonable to make a feature request?

(maybe this thread should be moved again, sorry...)

Moved back to Help forum.

It states very clearly in the wiki that sketcher point is not available outside of the sketch, it is a construction geometry only.
Use a Datum point or part point.

See Limitations:- Sketcher_CreatePoint

Bance wrote: ↑Thu Oct 22, 2020 2:06 pm It states very clearly in the wiki that sketcher point is not available outside of the sketch, it is a construction geometry only.
Use a Datum point or part point.

See Limitations:- Sketcher_CreatePoint

Ah, thank you for clearing that up!