This started out as a SolidWorks Gopro model file. I split off the mounting part, capped it then extruded the capped face to the clamp I modeled to fit my use. Rhino check says it’s a valid file. I seem to remember a while back having a problem with isocurves like this.
Hello - I am guessing you meant to make something like this - NEW_GARMIN_MOUNT_PG.3dm (1.9 MB)
I would stay away from EdgeSrf, that is misleading you into thinking you can finish a part without thinking about what it is you really want - if those parts are meant to be planar, top and bottom, which seems likely to me, then make them planar…
Thanks Pascal. However, I did not use EdgeSrf. I realize my problem came about when I extruded the capped section by just pulling the face. It doesn’t appear if I use Gumball extrude.