Multiple sketches in body seem to not make one solid body

[jusaca]

I just stared with FreeCad and was doing this exercise:
https://github.com/Flowwie/flowwie-free ... Lasche.PDF

In the accompanying video you can see at 8:41 that the combined body seems solid, as I imagined it would be.
But when I try to replicate this build I get lines crossing through the crosssection of the body, see the attached screenshot. I also attached the FreeCad file, just in case it helps to narrow down my error.

[Shalmeneser]

Refine = true on the last step.

[Shalmeneser]

* You just need 2 sketches if you use PartDesign_Hole.
* 25=25 ?!

[jusaca]

Ahh thank you, that solves it. So I always need to use the refine cmd as my last step? Interesting. Do you know why FreeCad isn't doing that automagically? Is there a upside to not do it?

The drill cmd also seems useful to avoid unnecessary sketches =)

* 25=25 ?!

What do you mean by that?

[Shalmeneser]

1) So I always need to use the refine cmd as my last step?
2) Do you know why FreeCad isn't doing that automagically?
3) Is there a upside to not do it?

1) If you want to. You can need it before a Fillet operation.
2) Edit > Preferences > Partdesign > General : Model settings : Automatically refine ...
3) Yes. Some errors can be caused by refine=on and are hard to solve (because you don't think it's that).

4) 25=25 ?!

4) You should avoid twice the same dimension in a sketch and use instead geometrical constraint (symmetry ?).

[M4x]

It's just a visual thing. In general, you don't need to refine.

[jusaca]

OK, I see, but it is not really just visual, right? If I export a step file without refining it also contains these two different objects. That's not exactly what I expect from a 3d model body and might result in problems further down the workflow.

4) You should avoid twice the same dimension in a sketch and use instead geometrical constraint (symmetry ?).

Ah that makes absolute sense, thanks for that feedback. I already saw it in your modified project file.

[Bance]

If I export a step file without refining it also contains these two different objects.

That is not the case, please read this page Part_and_PartDesign.

[chrisb]

One PartDesign body describes indeed always a single solid. Even if you want, you can currently not have more.
I am one of the guys arguing to leave Refine=false by default. Not because I like the additional seams, but rather because it causes less trouble. Troubles may occur slightly more often, but they are not very serious, while errors caused by an unnecessary refine can even for experts be very hard to detect.

[jusaca]

You guys get me confused.
I checked the exported step file with an online step viewer: https://sharecad.org/viewer

And as you can see in the screenshot it does indeed make a difference in the exported step file. Is this maybe a config thing on my side? I actually doubt that, as the linked article about the difference between Part and PartDesign is rather explicit