Ball bearing washer/cone

thingiverse

I have printed a universal spool holder, available for download at http://www.thingiverse.com/thing:572371. Upon testing, I found that when attempting to tighten the nut on both sides with a ball bearing and standard washer, there is excessive pressure on both sides resulting in considerable tension during unwinding. To alleviate this issue, I designed the bearing cones using 8mm materials. If you wish to resize it, feel free to do so: the red component in the middle of the nut and the ball bearing can be adjusted as needed.