Hello,

First time poster here and relatively new to SolidWorks in general.  I am having trouble extruding basic shapes (rectangles) from a cylindrical surface.  I am making a model of R2D2 for my manufacturing processes class.  In order to put features on the body of the robot, I first revolved a sketch to make the cylindrical body.  I then began adding features by doing cuts and extrusions from sketches that I made from "surface/face/plane".   The technique I am using was a success for the front and head of the robot, but for some reason now that I am doing the back it is giving me the rebuild errors:

"The projection of the sketch on the surface failed.  Please check that the sketch is completely within the surface/face/plane and that it is projected onto only one surface."

As far as I can tell, the entirety of the sketch is within the green face of the cylinder, and it is only being projected onto that one face.  Can anyone figure out what I am doing wrong?  Thank you for your help!

-Dave