As shown on the test file: the **second** revolve, based on the workplane resulted from the first resolve, breaks the surface. Solvespave version: **Version 3.0 (3.0~bc4924ae)**, macOS Catalina Version 10.15.2   [second_revolve_test.slvs.zip](https://github.com/solvespace/solvespace/files/5079984/second_revolve_test.slvs.zip)