I've been looking for a long time at what Lulzbot does and integrates with their product. I noticed on all axes, they installed bearings as idler. I wanted to try so here is the result. I modified the Zbrozek motor mount (https://www.thingiverse.com/thing:3122625) to align with the idler.
What you need for the idler:
2 608-2rs bearing ABEC9
2 nylon M8 washer
1 28mm of 8mm smooth rod
reuse the 2 M5 screw of the old idler (M5x10)
What you need for the motor mount:
1 625-zz bearing
sandwich together nylon washers and bearings like this: washer, bearing,bearing and washer.
insert them in the idler support.
take the smooth rod and insert in bigger support hole and push it. align washer and bearing along the way so the rod can pass through.
With a plier gently push the bearing in the motor support.
install it on the bear frame. Align the motor support with belt from the belt holder. The belt need to be in the middle of the line on the motor mount. secure it with the M5 screw and t-nut. unscrew the set screws on the pulley so it can be loose. Insert the stepper motor in the motor mount and screw all three M3 to secure the motor. Align the center of the pulley with the line on the motor mount and tight all the set screws.
Pass the belt on the pulley and idler and attach it to the belt holder.
now screw the idler to the frame. align the idler so belt is in the middle of the two bearings.
Belt should be tight and sound like a bass strings.