Spool roler for spool holder

I printed the https://www.thingiverse.com/thing:2022798 spool holder for the anet A8, but as I could only get 5/16 rods, the wheel were not stable.

By using a full length tube, the tube roll easily and the 608 bearings are kept straigth. The tube can be used on other holders. Print 1 to use with the original spool holder right away by using it in the spool center. Print two to use with the 2022798 spool holder, the original wheel wont be required. Can hold spool up to 70mm wide, larger will require to elongate the insert.

The tube has 2 parts which have very small overhangs, so no support are required. The two parts are pressed together and requires no glue.