Can't split or cut the object simply! Bug?

[Anonymous]

I used to have such situation a few time before, but this time I can't fix it with any ways. 

[jhackney1972]

The existing body acts as though it is already split.  Offset the YZ plane to create another plane, even the slightest bit, and it splits easily.

[Anonymous]

Thanks John for your quick reply. That's a solution I used before, but that bring more unnessary work for later operation (like cut/boolean operation with other symmetric parts, then I need to change all other parts cut line and make them not symmetric parts) and potential problem like have 2 seams in the middle and still can't split or cut in half. All operation with symmetry plane would have more or less trouble and I would waste tons of hours to fix them if I continue build with this problem from my previous projects experience. That's why I wonder if the dev team can fix it from the kernel.

[jhackney1972]

This is a workaround, not a solution to your core body problem.  It would seem that the body thinks it is already split so what I did was remove a 2mm section, then replace it and then the body acts as it should.  Model is attached.

[Anonymous]

Right, thank you John for the workaround although it changed the curvature. 

Let's see if the dev team could fix it. 

[daniel_lyall · Accepted solution]

If you do a unstitch then a stitch you can then delete the offending faces and patch the hole then stitch again then you can split the body.

Or turn the timeline off and merge the 2 facies and then split it.

It is the line going down the middle that is the problem it is a dirty surface.

[TrippyLighting · Accepted solution]

I have another approach / workaround , which does not require compromises in precision.

See attached file and go through the timeline step by step.

[Anonymous]

Thanks @Anonymous and @TrippyLighting for the surface solution and example, that keeps the curvature.

The "cut half" issues brings me trouble and concerns sometimes, so I often check the section analysis in symmetry plane to ensure no problem there.  You can see this case is interesting from @TrippyLighting fixed project file. 

My process was :

1. Create the surface in "FORM" tool with symmetry on.

2. Cut the surface in half  by "split" or "extrude"

3. Add features on the surface

4. Mirror the surface

5. Thicken the surface (it brings issues often if this step is before the "mirror" operation)

I also had the trouble for "mirror w/ join on" a symmetric surface or symmetric object sometimes in the process. The new "tolerance" setting feature helps, but not always. 

Who should I tag for getting the dev team attention?