On building the shredder i would sugest to rotate the holes for the bearing to 45°, so when there is a need of tighting all together, you wont have the fixed big knives standing in your way.
the picture is just a scribbled example.
i have now allmost finished no 0ne. Two to come.
Stefan
that actually makes a lot of sense @stefanh1510! Much easier to access them without fully taking apart the entire shredder. 
Guten Abend zusammen,
great perception stefanh1510.
In my case I rotated the holes to 30°. in case of collision bearings with L profiles.
But I am using bearings CHDH20. See attached picture.
