Filament holder - 31+mm reel holder (part 4)

Having got a 3rd different centre-hole-sized filament reel this week, I decided to create a simple quick-change holder for my Lulzbot AO-101.

This part is the 31+mm reel holder. It slides over the bolt end (part 1) and is a snug fit.
I'm also going to be using this with loose coils of filament.

Links to the other sections here:
main bolt end: http://www.thingiverse.com/thing:172267
50+mm reel holder: http://www.thingiverse.com/thing:172269
73+mm reel holder: http://www.thingivers