Bearing Retainer for Wankel Rotary Fidget spinner

I didn't have any countersunk M3 bolts, but did have some button-head, self-tapping ones. I changed the back-side of the bearing retainer to fit the screw a little better. I used an M3x12 self-tapping screw and it worked very well. 

This is such a great model, so I am pretty pleased I was able to add something very small to it.