Assembly3 attaching with multiple holes

[DaAwesomeP]

Hello!

I am attempting to attach some parts to a grid of holes.

For the longer flat piece, I am able to do two AxialAlignments, but then a PlaneAlignment after that does not work. For the other pieces, I cannot do the two AxialAlignments. The Attach constrain does not align them properly.

How should I constrain them together?

attach.png (153.85 KiB) Viewed 3073 times

File was too large to attach: https://drive.google.com/file/d/1bKerxE ... sp=sharing

Thanks!

OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 2021.528.24301 +3572 (Git)
Build type: Release
Branch: LinkStage3
Hash: 1578dc89cb181b96e75d9fb128d82b0ec1460291
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.0
Locale: English/United States (en_US)

[jpg87]

For the longer flat piece, I am able to do two AxialAlignments, but then a PlaneAlignment after that does not work. For the other pieces, I cannot do the two AxialAlignments. The Attach constrain does not align them properly.

Hello,
If I answer your question strictly, you must put the constraints that remove the desired DOFs with the minimum of redundancy.
For example instead of 2 AxialAlignment (which leave an axial displacement but with an over-constrained positioning), use a PlaneCoincident between 2 circles, then a SameOrientation between 2 edges which must remain parallel.

If you don't have a lot of experience with Assembly 3 and given the size of your project, I think you need to be more rigorous although it might seem overwhelming.

I suggest you visit my website http://help-freecad-jpg87.fr/02_ass_ind.php

Then if you have any problems, I can help you.

[DaAwesomeP]

For example instead of 2 AxialAlignment (which leave an axial displacement but with an over-constrained positioning), use a PlaneCoincident between 2 circles, then a SameOrientation between 2 edges which must remain parallel.

I tried that and the PlaneCoincident and SameOrientation work independently, but in combination I get an "inconsistent constraints" message and they do not align.

If you don't have a lot of experience with Assembly 3 and given the size of your project, I think you need to be more rigorous although it might seem overwhelming.

I suggest you visit my website http://help-freecad-jpg87.fr/02_ass_ind.php

Then if you have any problems, I can help you.

I will be sure to check it out now, thank you!

[jpg87]

I tried that and the PlaneCoincident and SameOrientation work independently, but in combination I get an "inconsistent constraints" message and they do not align.

Hello,
I tested on my end and I have the same problem which did not occur before. I used another approach and got this :

Asm3Rover.png (74.8 KiB) Viewed 2857 times

If this is what you are looking for, I will make my file available and give you all the explanations you want.

[jpg87]

SameOrientation

After an exchange with Realthunder, I noticed that the SameOrientation constraint prohibited all rotations between the two constrained objects (3 DOFs remaining), whereas I mistakenly believed that only the normals were made parallel. On the other hand, the MultiParallel constraint renders well (and only) the normals to the designated planes (4 DOFs remaining).

And yet that doesn't seem to work either!

While waiting for Realthunder's response, I had used the Perpendicular constraint between two judiciously chosen surfaces, so I am forced to stay on this constraint for now.

[DaAwesomeP]

Thank you for trying it all out! I wasn't sure if I was really doing something wrong or something wasn't working as intended because it kept getting over-constrained by constraints I didn't think would lock rotation or movement in a certain axis. I was able to get it to work (meticulously) by using other constrains. There were a few points where I got one piece lined up and just Locked it and removed its other constraints (as a temporary workaround).

https://drive.google.com/file/d/1w4lHAo ... sp=sharing

final1.png (134.19 KiB) Viewed 2571 times

final1_constraints.png (16.66 KiB) Viewed 2571 times