I needed to move my spool holder out a little further since some of my larger spools were still rubbing. I know I could have printed longer arms, but I didn't want to waste the material, and this will keep the holder MPSM printable.
These will just snap into the existing holes on the arms, and are tight enough to not need any glue. They come back out fairly easily with a small flathead screwstick.
Pictured universal spindle: http://www.thingiverse.com/thing:2220924