Ring radii and the number of segments. Shape factors for the cone ends.
Cone wall thickness. The amount of "dish" if any. Whether any of the top
and bottom surfaces are to be horizontal when the ring is assembled.
Notes :
Once you have specified your ribbon a diagram will appear at the bottom of this page. The thicker black line on the diagram is the cone and lathe axis. If a red line appears, this shows the orientation of the upper cone part when the ring has been assembled. That is, this line will be horizontal after assembly. If there is no red line the joint line between the upper and lower work pieces will be horizontal after assembly.
The dimensions given in the table are the minimum needed. You should make some allowances (say 1/8th inch or 3 mm) on the work piece thicknesses and the work piece width. Try to cut the work piece length to the size given as this length governs the size and position of the chords you will measure during turning. If you want an allowance increase your ring outer radius and decrease the inner radius before you begin specifying the design.
If error messages appear either before or after you click on "calculate", just change these values and continue or click "calculate" again.
If you do not like the design just change those values you think will improve it and click "calculate" again.
The upper work piece is the part you will use to make the specified ring. The lower work piece can be made of waste wood. Make at least as many cones as there are segments in the ring.
If the diagram shows a symmetric design you will need to make at least half as many cones as there are segments in the ring. You will use both upper and lower parts of the cone. The wedge can be made of waste wood.