I have tried to draw a simple C-shaped spindle bracket with no luck. It keeps coming out a shell. I draw a c-shape with lines, 5" tall, 2.5" top and bottom and 2" wide. I offset to thickness of .3125 and close the ends. When I exit I get a shell. I have also tried in sheetmetal. It will work but, the inside radius will not change. What am I doing wrong?