Designed my new lathe beltsander, and I'm already busy with making parts.
The beltsander is lathe powered.
Use two separate belts, the same as used on small hand beltsanders.
These belts are very cheap, one belt cost nearly 2 euro.
Use one beltsander for flatten the smaller half segmented rings, and both for the larger.
This is the second piece of machinery, to use together with my new mitre saw for making more perfect segmented rings, anyway I hope so