Precision Piezo 20mm disc to LM8UU bearing mount

Edit 8/13/2018:

So... I actually built and tested this. I deprecated the long version, as the small one is plenty strong enough, and has more than enough advantages to decide not to need the long version.

A couple of problems that I've addressed in the new version:

Using the 4 screws to hold the whole assembly together puts the stress of holding the bearings on the piezo disc. If your printer didn't make this exactly to dimensions, or if your LM8UU bearings were slightly larger than spe