I made holes for the M3 nuts, not all of them are used, but they can be useful if you need to lock the parts very well to each other. I also made deep holes for the M3 screws, so if you want to use longer screws, they have places already.

There is an attached file for the rollers if you decide to print them instead of the bearings, make sure you make their edges smooth, so you will not cut the tubing.

Also the triangles that hold the bearings, are marked by a line as in the pictures, that sides must be in the same vertical line, that sides are locking the triangles to the motor’s shaft to prevent the triangle from slipping when the shaft is turning.