I use maple and walnut and start with the maple stacked on a piece of walnut because the pattern on maple is easier to see when cutting. I have two sizes shown here and have finished products from both.
I start by drawing tangent circles and then drawing a circle around the both of them. It is important to draw these accurately because I sand to the lines for fitting the pieces together/
Then I cut on the outside of one circle and the inside of the other and never cross the line because it is my pattern for sanding.
This is the result of this little pattern:
On larger ones it is the same process:
The top and bottom could be held together with double faced tape but I just used glue outside the pattern I was saving.
I drill the hole through both pieces before cutting out the pattern. The diameter of the small hole is .2 x the larger diameter
Then the sanding starts. I sand them in a pair first and then sand individually to fit them without any light gaps.
Then they are glued together and contrasting plugs are turned for the small holes and a spigot is carefuly glued on center to hold the part in the turning process. After turning the first side, I cut a mortise into the back to hold the part while grooving the front.
That is the method I use to make this pattern. Thanks for looking!!
-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!