The filament sensor bolt is a little short for the M3 nut slot. I suggest using a longer M3 bolt to get it to fit, an M3x12 will work. You will also need another M3 hex nut.

From the original post:

Version 2.0 - Has sliding rails to easily adjust for different spool widths
My quest continues to keep improving my filament spool holders. Since I frequently change spools and almost every spool I have has a different width, I decided having something that could easily slide and adjust as opposed to discrete positions would be faster and easier. An added benefit of this remix is that the spool holders stay down and can't pop off. I've included any old files needed from my first version, https://www.thingiverse.com/thing:2521463.

(FIX: Thanks to signaturefish, He pointed out that there was an alignment problems with side holes on the TUSH2-Outside piece. I also tweaked the rail cut that was off on one side by a small amount on the TUSH2-Inside piece--noticed by eowindel. I've removed the old ones and replaced them with fixed versions 1.1. )

This version has the following benefits.

Sliding rail for adjusting to any width spoolTUSH won't pop off railsTUSH inside and outside pieces can accommodate a nut and blot to hold it together(M3 nut and M3x12 bolt) - This is optional. They will force fit and hold on bearing.Outside piece has a raised guide to keep the spool from coming off the side.Still can accommodate spool holder arms to keep the spool from being pulled off the TUSH when the spools get lite or tangled. I usually to be safe use at least one with any spool I'm using.