Over the weekend I used a jury rigged approach based on some of the
designs but much simpler.

I had a piece of 1/2 inch baltic birch plywood that I had made a mistake
in cutting.

I knotched one end with a cut wide enough for my bandsaw blade and
several inches deep.

I drilled a few holes in to receive a finish nail that I cut short so
less than 1/2 an inch would stick out when driven through a hole from
the other side of the plywood.

Then I mounted a chunk with a shallow hole drilled in what I thought
should be the center and moved the plywood until the chunk was nearly
contacting the blade. I made sure that the hole with the nail was lined
up with the tip of the blade and then clamped the plywood to the bandsaw
table.

The approach does not require anything more than a few holes because I
can reposition the plywood so the center is in the correct place.

The plywood is stiff enough that there is no flexing.

After a couple smaller chunks I put a large piece of dry elm log almost
9 inches thick and with a weight of 30-40 pounds onto the jig that had
been cut in half. Taking it slow and easy I was able to cut the log
into a round blank about 14 inches across. I could have made it bigger
but I wanted to cut out some serious checking at the ends of the log

william kossack wrote:
At one point I remember seening the plans for a jig to help cut blanks
round on a bandsaw. I've decided I'm a meserable failure at cutting
them round free hand.

Can anyone point me to some plans?