I am pretty happy with this version.
The idler pulley mounts to one side of the level. My other designs used a pocket like the thingiverse version, but I was having a few tolerance issues with my bigger bearing. The put the big knob at the top because the end of long skinny tapers tend to start to peel up on some of my prints. The bearing mounts with a button head M4. It self taps into the hole. The head is just below the heatsink so I don't think it will back out. There is a thin washer under the bearing so only the inner race touches. I should probably print that little offset.
The spring support block does not cross the to the other motor hole like the thingiverse version because I needed the lever to be full width for strength. It just has a little nub to prevent rotation. The spring is centered so the is no real torque on it.
I somehow screwed up the alignment of the spring pockets, so it is at a slight angle.