Can't get power button symbol right. Need help cutting letter 'O' and filling gaps I'm having trouble making a 3d power button symbol. I want it to look similar to this one. Here is the .blend file I'm working with, if this helps anyone understand what I'm trying to do.
Using the cuboid that's over the letter 'o', I can cut out the portion of the letter 'o' that the cuboid occupies, however, the remaining ends of the letter 'o' are left open.
I can't find a way to fill the ends, and preferably round the ends. If anyone can show me how to do this, that would be a great help!
Here is how you can create a power button:


Add a circle.
Enter edit mode.
Selected it(A) and extrude + scale it inwards.
Delete(X->Faces) some of the at the top of the circle as such:

Add a plane into the scene.
scale the plane so that it takes the shape of the line:

Select All(A), and extrude it upwards until your power button is as thick as you want it.
To add rounded edges: select the line, as well as the faces on the inside of the cut. also select the rings(Shift-Alt) that make up the edges of the '0'.
With all those vertices selected hit Ctrl-B. Use the scroll wheel to control the amount of cuts(I'd recommend 4).
Select all and hit W->Shade Smooth.
Rotate it on the Y axis to 90 degrees (RY90) .


Done!