Hi--I have a mechanism model where I have a constraint of "Point-on-Surface". The surface begins with a surface on the inside of a cylinder --- works fine. When I change the shape of that cylindrical surface by introducing a flat on one side, the surface is no longer one surface, and the constraint fails. How can I make the flat to be part of the original cylindrical surface? In other words, can I merge the 2 surfaces into 1, or? I am not able to solve this issue. Any suggestions would be appreciated ---Thanks.