Cannot place sketch at desired position

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redman
Posts: 19
Joined: Sun Feb 13, 2022 9:02 pm

Cannot place sketch at desired position

Post by redman »

I've used Draft to Sketch to bring a sketch from RpiZero (pcb corner @ 0,0,0) to RpiZero_Centered ( pcb centroid @ 0,0,0) and having a hard time fully restraining the new sketch. Reason for copying the sketch: already digitized in top model , just need to place at a different location.

In attached FreeCAD file ( v0.20):
RpiZero.Sketch006 = existing sketch of miniHDMI port
RpiZero_Centered.MiniHDMI_Sketch1 = initial sketch created for digitizing miniHDMI port ( with the intent to re-create geometry from scratch). MiniHDMI_Sketch1 was only used to "place" the draft sketch in the right location and is no longer needed
RpiZero_Centered.Sketch022 = sketch created using Draft to Sketch ( steps shown in screenshot below)


I could not tie RpiZero_Centered.Sketch022 to origin or axis ...or edge of PCB ( to place it on correct location along the PCB) ... Not sure why ... I've attached updated FreeCAD file and a screenshot showing the challenge.

Thanks in advance!
Attachments
PiZeroPCB-V1-1_3-Ver009-030818_wTBlock_v2ab_06-21-22.FCStd
(405.7 KiB) Downloaded 9 times
DraftSketch_2MoveGeometry_How2_06-21-22.jpg
DraftSketch_2MoveGeometry_How2_06-21-22.jpg (364.85 KiB) Viewed 740 times
DraftSketch_3dview_06-29-22.jpg
DraftSketch_3dview_06-29-22.jpg (182.16 KiB) Viewed 740 times
DraftSketch_Constraint2Origin_06-21-22.jpg
DraftSketch_Constraint2Origin_06-21-22.jpg (212.87 KiB) Viewed 740 times
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thomas-neemann
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Re: Cannot place sketch at desired position

Post by thomas-neemann »

redman wrote: Thu Jun 30, 2022 3:42 am ...
here it works
Bildschirmfoto_2022-06-30_07-31-35.png
Bildschirmfoto_2022-06-30_07-31-35.png (59.67 KiB) Viewed 720 times

Code: Select all

OS: Ubuntu 20.04.1 LTS (XFCE/xubuntu)
Word size of FreeCAD: 64-bit
Version: 0.20.29177 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 0.20)
Hash: 68e337670e227889217652ddac593c93b5e8dc94
Python 3.9.13, Qt 5.12.9, Coin 4.0.0, Vtk 9.1.0, OCC 7.5.3
Locale: German/Germany (de_DE)
Installed mods: 
  * InventorLoader 1.3.0
  * Curves 0.5.0
Gruß Dipl.-Ing. (FH) Thomas Neemann

https://www.youtube.com/@thomasneemann5 ... ry=freecad
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Willem
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Re: Cannot place sketch at desired position

Post by Willem »

You need to do 4 things
- Give sketch022 support to the X-Z plane
- Change position of the sketch to coordinate 0 0 0
- Open sketch and bring the shape to the centre
- Close the sketch and change position
phpBB [video]
chrisb
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Re: Cannot place sketch at desired position

Post by chrisb »

- To keep close to your workflow: Instead of steps 1-5 you should rather copy paste the sketch. This may preserve some unwanted references, so before dragging it to some other place, you should edit it and remove all external references. Remove the attachment too.

- Even better would be to use a Sketcher CarbonCopy

- Draft Move is not suitable here. See Willem's post about attachment.
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redman
Posts: 19
Joined: Sun Feb 13, 2022 9:02 pm

Re: Cannot place sketch at desired position

Post by redman »

Thank you all for taking the time to reply! Really appreciate it!

I tried to use Copy/Paste ( created Sketch023 then again -024- for screenshots) ...I managed to get the new Sketch024 under new Part then dragged under HDMI part. However, I am still not able to create a horizontal restraint even after following the video and instructions posted. In the attached FreeCAD file see Sketch024 ( this is the one I worked on).

I even tried the file received from thomas-neemann and deleted the horizontal constraint to Z axis, moved sketch on the other side of axis and still could not re-create.... not sure what I am missing here!?

chrisb: I am not sure how to remove external references after pasting a sketch ( before dragging to desired location)? I tried to pay attention to the selection options during COPY operation and I can tell you that selecting the right dependency is not as simple as expected ... I hope I made the right selection ( see screenshots). However, I suspect that is not what your recommendation meant :)
Attachments
PiZeroPCB-V1-1_3-Ver009-030818_wTBlock_v2ab_06-30-22.FCStd
(410.75 KiB) Downloaded 3 times
1-Copy_Sketch06_Settings_06-30-22.jpg
1-Copy_Sketch06_Settings_06-30-22.jpg (324.02 KiB) Viewed 609 times
3-change_sketch024_support_to_XZ_06-30-22.jpg
3-change_sketch024_support_to_XZ_06-30-22.jpg (330.21 KiB) Viewed 609 times
4-CopyPaste_Sketch024_MapMode-Deactivated_06-30-22.jpg
4-CopyPaste_Sketch024_MapMode-Deactivated_06-30-22.jpg (219.98 KiB) Viewed 609 times
5-CopyPaste_Sketch024_cannot_set_constraint_06-30-22.jpg
5-CopyPaste_Sketch024_cannot_set_constraint_06-30-22.jpg (163.04 KiB) Viewed 609 times
freedman
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Re: Cannot place sketch at desired position

Post by freedman »

I took a few minutes and did some editing to your file. This is how I would approach the design. I cloned the board for the next layer presuming the boards are the same. I didn't finish the board sketch but it's close.
Attachments
board3.FCStd
(232.48 KiB) Downloaded 4 times
board2.png
board2.png (239.75 KiB) Viewed 577 times
chrisb
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Re: Cannot place sketch at desired position

Post by chrisb »

redman wrote: Fri Jul 01, 2022 1:40 am chrisb: I am not sure how to remove external references after pasting a sketch ( before dragging to desired location)?
Yes, do the following before dragging, otherwise the sketch can flip to an undesired layout.

Either:
- enter Sketcher by double clicking
- Remove all external references, they are purple and in the Elements list you can recognize them by their purple color too. They are always at the end of the list. To be very sure, you can check the "Extended naming" box and see "External Edge ..." in the list.

Or:
- Use Sketcher ValidateSketch to remove all external references.
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redman
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Joined: Sun Feb 13, 2022 9:02 pm

Re: Cannot place sketch at desired position

Post by redman »

chrisb - I used ValidateSketch on Sketch024_CopyPaste and found no errors/references to fix. Enabled EXTENDED NAMING and no purple items show in ELEMENTS list.

freedman- thanks for the file... looking good....the new PCB I was working on , is supposed to be identical with the one with the PCB corner @ 0,0,0. TRYING to copy the ports from the old part, before deleting it......instead of re-creating them from scratch.
The new one ( RpiZero_Centered ) is supposed to have the PCB centroid at 0,0,0 thinking it would help with mirroring parts/holes using symmetry... I am not sure it will be that much more helpful... maybe it would be more beneficial if the mid point of the longest side of PCB is at 0,0,0... maybe it is my lack of experience with FreeCAD :)
However, no matter where the PCB is placed, the problem I am having is creating restraints. I tried to recreate Constraint22 and for some reason I am not able to select the Z axis as a reference point ! How come you were able to create this constraint? What am I missing?
Attachments
cant_reference_zAxis_07-01-22.jpg
cant_reference_zAxis_07-01-22.jpg (209.14 KiB) Viewed 502 times
edwilliams16
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Re: Cannot place sketch at desired position

Post by edwilliams16 »

Looks like you have line(s) on top of the z-axis (dimension references?) that prevent you from selecting there.
You can also get distances from the origin by selecting the vertex alone. The subtle difference is that the distance is signed.
redman
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Joined: Sun Feb 13, 2022 9:02 pm

Re: Cannot place sketch at desired position

Post by redman »

edwilliams16: thanks for the reply! While I am not sure what line I have on top of Z axis, I was able to use the vertex (instead of Z axis) to create a constraint! ... It's funny because I was aware vertices can be used but I believe I have not tried it after changing the sketch support to XZ... That's my only explanation ! :)

Thanks again!
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