Spring loaded extruder for Leapfrog Creatr

The Creatr from Leapfrog (www.lpfrg.com) has a fixed idler ball bearing. I wanted to replace this by a spring loaded type to allow better control over the filament feed and allow for an easier filament change.
After a few different ideas, the Mk7 minimalistic replacement extruder seemed a nice design to start with and here is the result.
Now changing colors is actually a fun thing to do ;)
Update: I found that the pressure on the filament was not always enough so I moved the spring and com