我也有买了一个可是还没拿到，
先寄信去问了一下不均匀的问题，
官方回复如下：
The issue with your un-level burr is most likely the inner burr itself. Here are three steps to try and center it:
1. Remove the inner burr take a look at the plastic inserts in the top and bottom of the inner burr. If these pieces are not pressed all the way into the ceramic, they will cause the inner burr to sit crooked on the axle. To level out the top piece, flip the inner burr onto its top and press it firmly on a hard surface.
2. Replace the inner burr on the axle press it down so that it is touching the outer burr. Screw on the thumbnut as tightly as you can.
3. If the inner burr is still not sitting straight, remove it again, spin it 180 degrees, and replace on the axle in the opposite direction (The axle has 2 sides, so the burr can only be replaced 2 different ways). Then follow step 2 again to retighten the thumbnut.
不过还没拿到东西无法实际操作，分享一下。