I was frustrated by how the Ultimaker 3 stock filament guide works, especially with wider spools which jam up.
This front mounting filament guide is remixed off the original Ultimaker part: https://www.youmagine.com/designs/ultimaker-3-spool-holder
It simply clips on the front of the spool holder - the cable cover can not be used with this guide. The white insert from the original guide can be put in this one if wanted.
Creative Commons Attribution Noncommercial Share Alike