The most obvious change is that the bars curve, a bit like a balafon or gyil. With a new way of suspending the bars on rubber grommets instead of metal eyebolts, the ringiness and clarity of the notes is improved. Weeellll, I can't say that scientifically for sure yet, but the first two of these I've made sound better in that regard than my "classic" Minnie Ms.
My goal was to design this instrument so that there are NO metal parts. Success! There are NO metal parts in it! The five plywood components interlock with ears that insert through slots, held together with a few pins - not unlike the Amish style tressle dining table I build for us many years ago.
If you look close you may see a couple of the rubber grommets I am using to suspend the bars, in place of the traditional eyebolts. The new Minnie M stacks one on top of the other, and stands upright with a small footprint for storage - just like the old ones.
Like all of my instruments, the bars are removable, so you can swap out F# and Bb bars. Or order your own scale and tuning. Now if I can just figure out how to make these instruments buzz....