FreeCAD Forum

Hi all

I stumbling over some realy strange behavior (bug?) of Arch. It seems it's not possible to line-up 4 squares !
But let's start from the beginning: I created a new sketch and draw 4 rectangles which represent 4 Plywood-Panels each of 2.5m x 1.25m.
These panles shall be placed next no each other (without any gap). After finishing the sketch I switched to Arch and created a Structur-Object from it whth a hight of 20mm. But unfortunately the 4 panels will not show !
I only get a "general issue" error message saying: "Structure has an invalid form" ??

Any idea ?

may24x wrote: ↑Wed Apr 27, 2022 10:47 am But let's start from the beginning.

If you want to extrude a sketch it must not contain T-connections. Duplicate edges are also not allowed. In this case you should create the outline of single panel, extrude that, and then array the result.

Hi Roy

Thanks for the reply ... but no, that doesn't work.
I fiddled around a bit but couldn't solve the problem. I still belive this is a FreeCAD bug. Maybe I got one step further:
So again, here we have our 4 panels in Sketcher and as extruded Object in Arch
But now, I sat some distance values that would place the two object next to each other:
Now, that instead of two solid objects, FreeCAD turns them into a star-shaped body ???

may24x wrote: ↑Wed Apr 27, 2022 2:01 pm no, that doesn't work.

You are wrong there. See attached file.

may24x wrote: ↑Wed Apr 27, 2022 2:01 pm Maybe I got one step further:

The information I have provided regarding the limitations of sketches represents the current state of FreeCAD. Of course you are free to ignore this.

Ah I see ... you use an Array to multiply the underlying objects.
Not quite what I had in mind. It works, true, but the idea is use a sketch as a 2D Layout (plan) and then form a 3D-Model from it.
So the Arry method will not work for me. If I'd draw another object it would get also multiplied.
Also it doesn't solve the issue that (e.g.) you can line-up three panels perfectly while the fourth one don't

With a PartDesign_SubShapeBinder you can reference elements from a sketch. Shapebinders can be extruded.

Roy_043 wrote: ↑Wed Apr 27, 2022 11:18 am If you want to extrude a sketch it must not contain T-connections. Duplicate edges are also not allowed. In this case you should create the outline of single panel, extrude that, and then array the result.

In this special case where there are double lines the Part>Extrude works.

But it's not only a question of workarounds (I can think of some more). I am not an Arch expert, but it is unclear to me:
- If the given example should work with 4 panels?
- If it is just by chance and not by design that it works with three panels? That would mean it should be modeled in a different way.

AFAICT there are 5 examples in this topic. Which are you referring to?

With the sketch in the file from the OP Arch_Structure can work if you choose "Cheese" as the "Face Maker". But the result then is a single solid, which is not what may24x wants I think.