Bob Warfield posted this in Brian's super-duper horizontal double acting thread but I didn't want hijack it....
Lots of ways to skin the flywheel cat. While you've already bought your brass blank and no doubt intend to continue in that vein, I thought I would post a link to The Engineman's built up flywheel as an alternative for others:
David: There are two important considerations in a segmented flywheel. The size and the speed.There can be a significant centrifugal force on the rim of a flywheel and soft solder has almost zero strength in a butt joint in tension.
Stan in Leduc, Alberta, Canada. 53.40NĀ* 113.5W
Old, but still on the right side of the grass.