Round in solid breaks

By moving selected edges into a solid, rounds sometimes break.

  • moving 1mm in red direction
  • see the red arrows
    Does anyone know this mistake?

Hi @user1951 best is if you can share a file that illustrates the issue you are having. I know that rounds sometimes break in Solid Editing, but every case is (slightly) different.

If this happens, what I often do, is explode the solid and then do the solid editing, and join back. Not 100% guarantee for success, but it often gets the job done.

Hello Gijs,
I found the cause.
The picture shows a holder for a glass railing of a staircase. The file is set in unit meters. This is common in architectural implementation planning.

The radius at the point shown is 1.5mm.
The tolerance settings of the file have no decisive influence on the problem described. The roundings do not break everywhere.
In one meter file you cannot reliably build such details, as I know now.

If I copy the holder into a file with a unit millimeter and do the same, nothing breaks. Axial moving the surfaces works without any problems.

When rendering with Vray, this file occurred to pixelated shadows during close-ups from threads.
In principle, this seems to have the same cause.

Hi Tobias -

You still haven’t posted a file, but it sure sounds like it does.

Your file tolerances need to be at least one order of magnitude tighter than the smallest feature.

Hallo Wim,
I have all the objects except for the holder from the
File removed. …otherwise too big, etc.

Auswahl H1_copy.3dm (11.5 MB)

Honestly, this is not a very robust operation for non-planar trimmed faces like these fillet. I understand the temptation and the idea, but the truth is it is unlikely to work well in this context. Rhino fillets are not ‘procedural’ features, just dumb surfaces that have no idea what created them.


It is a simple solid with right angles.
As a rule, small axial changes make no mistakes.

I wish I could always change the fillets.
Also remove the fillet or convert it into a chamfer would be great.

I would like to briefly address another rounding situation.

See screenshot

I have seen that this is not a problem in the Solid Edge software. You don’t have to build it manually. You can always change the radius easily.

Correct - fillets in solid modelers are features that know how they are made and are re-created on edits to the input. Rhino does not do that.