got 15mm knuckles & want them to be 16mm?

[Serum]

robin's stuff is extremely precise and perfect

Normally yeah, but with the servo saver there is a small error. The bearings are pressed together if you tighten it, causing them to fail.

I've got 3 ue savers, and all three have the very same problem.

A bearing hole that is .13 mm too large is not good? have you got a caliper? if the bearing is a snug fit as you describe, the bit was most likely smaller.