Extruding a circle cut out of a circle in a sketch

[sprior913]

I'm trying to model a simple zero clearance insert for my miter saw which is a plate with 6 countersunk screw holes.  To draw this I started out with a sketch with a circle in a circle for the holes, my plan was to extrude the donut shape up to a partial height lower than the main body and leave the middle circle empty where the screw would go.  What I noticed was that I could select that donut shape and the preview would clearly show a hollow cylinder, but when I actually hit OK I'd end up with a simple solid cylinder - no screw hole.  Is this a bug or am I doing it wrong?

What would be the "proper" way to draw the sketch and then extrude the part for printing?  The other thing I noticed was that if I were to extrude the screw hole seperately from the rest of the plate I end up with 2 body elements - how would I merge them into one entity that I can export as a STL file?

[Phil.E]

In your images, I don't see the rest of the plate. Is it hidden? If so, try turning on the visibility prior to extruding the donut shape. If you want, you could attach the file, just use export archive from the 3-bar menu to get the file.

If you ever wind up with separate bodies that are touching and should be one body, use the Combine command under Modify menu.

[sprior913]

So I could clearly explain the donut extrusion problem I hadn't extruded the rest of the body yet.  Thanks for explaining how to combine bodies, now I just need to understand why the ring didn't extrude into a hollow cylinder.  The archive is attached.

[Phil.E]

The cause of this problem is the lines that extend from the center of the holes to the edge of the plate. I've logged this as an issue and given it to our development team. It should either not show you a good preview, or it should not fail. It should not show a good preview and then fail. So thanks for your input and help to make Fusion better!

Now to solve the problem: turn those lines into construction lines. They won't participate in the extrusion. Or sketch without them. See below.

[sprior913]

Now we're getting somewhere - how would I turn those lines into construction lines?

[Phil.E · Accepted solution]

First edit the sketch.

1) select the line

2) right click, and pick Normal/Construction.

It's toggle, so you can use the same command to turn construction into "normal" lines.