Concetric Semi circular stair

[rhys]

I'm trying to create a simple monolithic stair with three concentric semicircular risers. Stair boundaries are therefore inline with each other but separated by the diameter of the top riser, and extending to the diameter of the bottom riser. This results in a "serious error".
Any ideas ?

[aggockel50321]

I tried what you described & got the same behavior (serious error). Probably related to the 180° arc.

As a workaround, you could do 1/2 of the stair (90° arc) & mirror it over. You'll have to deal with the seam with the linework tool in any view you don't want to see it.

Or do an in-place family with extruded solids, or stack floor slabs.

[PeterJ]

Even with an angle of 179 between the boundaries it seems to be a problem

[rhys]

Yes, seems to start failing about 160 degrees. I've used 90 deg and mirrored as a quick work around, thanks