Assembling Model from pre-defined separate parts by linking

Post here for help on using FreeCAD's graphical user interface (GUI).
Forum rules
and Helpful information
IMPORTANT: Please click here and read this first, before asking for help

Also, be nice to others! Read the FreeCAD code of conduct!
User avatar
Vagulus
Posts: 850
Joined: Tue Jul 14, 2020 7:55 am
Location: Perth, Western Australia

Assembling Model from pre-defined separate parts by linking

Post by Vagulus »

I am trying to assemble a model from predefined parts by linking to the parts using Assembly4. With my assembly document (Linked Motuh.FCStd) and all the individual part documents open I use Insert a link to a part and link to my Master Sketch. FC inserts the sketch and automatically aligns the centre LCS to the default LCS.
211020 Master Sketch inserted - 640x429.png
211020 Master Sketch inserted - 640x429.png (61.97 KiB) Viewed 1588 times
So far so good.

I repeat the process for the block intending to align its LCS to the Master Sketch Centre LCS but I am not offered the option (see next post)
Attachments
Piston.FCStd
(15.37 KiB) Downloaded 20 times
Master Sketch.FCStd
(9.3 KiB) Downloaded 19 times
Linked Motuh.FCStd
(5.89 KiB) Downloaded 25 times
Block.FCStd
(14.42 KiB) Downloaded 18 times
"It is much harder to simplify than to complicate."
Joseph Kimble
User avatar
Vagulus
Posts: 850
Joined: Tue Jul 14, 2020 7:55 am
Location: Perth, Western Australia

Re: Assembling Model from pre-defined separate parts by linking

Post by Vagulus »

211020 No LCS Option Shown - 640x369.png
211020 No LCS Option Shown - 640x369.png (63.61 KiB) Viewed 1563 times
FC has taken the BlockPart and plonked it on top of the MasterSketch but the LCSs are not aligned. For some reason the Place Linked Part dialog does not show the LCSs in the parts I have imported.
Here's the Combo View close up
2211020 ComboView.png
2211020 ComboView.png (47.15 KiB) Viewed 1563 times
Before I go too far and foul myself up completely, where have I missed the bus? I have found tutorials which show me how to insert a part; steal the Body from it into the Assembly Parts Folder; then close the linked part without saving it. This leaves the body in the assembly for use but later adjustments to the part are not reflected in the assembly. That is why I am trying to use parts that are just linked (as some other modelling software does).

Is this possible in FC?
Does someone know of a tutorial which covers this - heaven knows I haven't been able to find one?
What have I got wrong?
"It is much harder to simplify than to complicate."
Joseph Kimble
User avatar
Zolko
Veteran
Posts: 2213
Joined: Mon Dec 17, 2018 10:02 am

Re: Assembling Model from pre-defined separate parts by linking

Post by Zolko »

Vagulus wrote: Wed Oct 20, 2021 8:04 am For some reason the Place Linked Part dialog does not show the LCSs in the parts I have imported.
that's because the LCSs are not in the "Part" container, they are in the child "Body" container. You have 2 options:
  • when using PartDesign Bodies, don't "wrap" them inside an App::Part, place them directly at the root of the document, and link directly to the Body
  • If you need to put it inside an App::Part (because of multi-body things for example) then you must "import" the LCS from the child into the top-most container. This imported LCS will follow the original LCS if you modify the underlying feature
I have found tutorials which show me how to insert a part; steal the Body from it into the Assembly Parts Folder; then close the linked part without saving it. This leaves the body in the assembly for use but later adjustments to the part are not reflected in the assembly.
Holy crap, where did you see this abomination ?

Does someone know of a tutorial which covers this - heaven knows I haven't been able to find one?
did you try these ?

https://github.com/Zolko-123/FreeCAD_Ex ... /README.md
https://github.com/Zolko-123/FreeCAD_Ex ... /README.md

(the second one wraps the Body into a Part, which was an old way to do things, I should update it)
try the Assembly4 workbench for FreCAD — tutorials here and here
User avatar
Vagulus
Posts: 850
Joined: Tue Jul 14, 2020 7:55 am
Location: Perth, Western Australia

Re: Assembling Model from pre-defined separate parts by linking

Post by Vagulus »

Thanks Zolko, I redrew the parts files with only Bodies and that resolved the LCS visibility issue. My assembly works https://1drv.ms/v/s!ArMxdUYEh9fKwAbloxR ... T?e=lfna2o but you'll probably freak at the way I did it. Is this the Tree View I should expect?
211022 Combo View 240x957.png
211022 Combo View 240x957.png (74.94 KiB) Viewed 1382 times
I'll attach the other files to the next post.
Attachments
Linked Master Sketch.FCStd
(8.02 KiB) Downloaded 14 times
Linked Motuh.FCStd
(8.22 KiB) Downloaded 16 times
"It is much harder to simplify than to complicate."
Joseph Kimble
User avatar
Vagulus
Posts: 850
Joined: Tue Jul 14, 2020 7:55 am
Location: Perth, Western Australia

Re: Assembling Model from pre-defined separate parts by linking

Post by Vagulus »

The extra files
Attachments
Linked Piston.FCStd
(14.46 KiB) Downloaded 16 times
Linked Block.FCStd
(13.32 KiB) Downloaded 15 times
"It is much harder to simplify than to complicate."
Joseph Kimble
User avatar
Vagulus
Posts: 850
Joined: Tue Jul 14, 2020 7:55 am
Location: Perth, Western Australia

Re: Assembling Model from pre-defined separate parts by linking

Post by Vagulus »

Vagulus wrote: Fri Oct 22, 2021 8:07 am Is this the Tree View I should expect?
Dare I assume that that Tree Structure is (somewhere near) correct?
Thanks
"It is much harder to simplify than to complicate."
Joseph Kimble
User avatar
Zolko
Veteran
Posts: 2213
Joined: Mon Dec 17, 2018 10:02 am

Re: Assembling Model from pre-defined separate parts by linking

Post by Zolko »

Vagulus wrote: Fri Oct 22, 2021 8:07 am Is this the Tree View I should expect?
Yes, that looks correct
try the Assembly4 workbench for FreCAD — tutorials here and here
User avatar
Vagulus
Posts: 850
Joined: Tue Jul 14, 2020 7:55 am
Location: Perth, Western Australia

Re: Assembling Model from pre-defined separate parts by linking

Post by Vagulus »

Zolko wrote: Sat Oct 23, 2021 10:03 pm Yes, that looks correct
Great
"It is much harder to simplify than to complicate."
Joseph Kimble
User avatar
Vagulus
Posts: 850
Joined: Tue Jul 14, 2020 7:55 am
Location: Perth, Western Australia

Re: Assembling Model from pre-defined separate parts by linking

Post by Vagulus »

Zolko wrote: Wed Oct 20, 2021 9:53 am that's because the LCSs are not in the "Part" container, they are in the child "Body" container. You have 2 options:
  • If you need to put it inside an App::Part (because of multi-body things for example) then you must "import" the LCS from the child into the top-most container. This imported LCS will follow the original LCS if you modify the underlying feature
I think I am in this territory now. I have a big (for me) project with 30+ Bodies in the document. These bodies were created inside a Part since, from what I have gathered, this is the correct procedure.
211025 Combo View.png
211025 Combo View.png (43.66 KiB) Viewed 1135 times
Now I want to pull one of the Bodies (A-03-003) complete with Local Coordinate Systems into an assembly using Assembly4. FC doesn't seem to keen on that idea - it only sees the Part (Air Pump) not the Bodies inside the Part.

Is the above quote hinting at the required procedure? I am thinking there must be a way to use this Part in an Assembly, otherwise using the Part container just makes the Bodies within it inaccessible and that wouldn't make much sense. Trouble is, I just can't find the way.
"It is much harder to simplify than to complicate."
Joseph Kimble
User avatar
Zolko
Veteran
Posts: 2213
Joined: Mon Dec 17, 2018 10:02 am

Re: Assembling Model from pre-defined separate parts by linking

Post by Zolko »

Vagulus wrote: Mon Oct 25, 2021 12:58 am These bodies were created inside a Part since, from what I have gathered, this is the correct procedure.
where did you get this-one from ? You can do this if you want, but only if you intend to re-use the entire Part with all its constituents. In this case the part is already an assembly ... this was actually one of the ways to do assemblies before v0.19 and the Link interface

Now I want to pull one of the Bodies (A-03-003) complete with Local Coordinate Systems into an assembly using Assembly4.
well, then no, this is not going to work. With Assembly4, you can only "pull" – link – parts and bodies at the root of the document
try the Assembly4 workbench for FreCAD — tutorials here and here
Post Reply