Recently I had to machine a few pieces after turning.

Because the very top of the part was supposed to be machined off, I could not clamp through the central hole like I often do.

Decided to quickly turn an expandable washer out of aluminum and a plastic spacer that would collapse a little bit under clamping pressure and allow the part to sit firmly against the base of the fixture.

I liked this method so much I am going to do the same next time I have similar part to make.

See pics below.

Later on i will try to post some more pictures of other setups I did.

All the pieces apart Fixture, spacer, expandable washer, FH screw Workpiece mounted on