Spool Roller

**Update 3/23:** *Per a user request I've added a large version of the spool roller to accommodate 3kg spools (270mm dia x 104mm wide).

**Update 12/13:** *Added a self-centering roller. The new roller has a concave profile that should keep the spool centered on the rollers. Although the standard rollers are working just fine, I decided to try to step up the design a little.*

This is yet another spool roller. I am currently printing with [Ultrafuse 316L Metal Filament](https://www.matterhackers.com/store/l/basf-ultrafuse-316l-metal-composite-3d-printing-filament-175mm/sk/MRDKJRRS?rcode=PPCADS&gclid=CjwKCAiAxMLvBRBNEiwAKhr-nIEDKaDHOJNrqssnExwD5cAWkd7OscF5hf6Mf-BXkP_NWNsaXPwiVxoCKRIQAvD_BwE). A spool weighs 3 Kilograms. I tried printing using my standard spool holder. But, the heavy spool applies too much weight on the holder. The excess friction causes extrusion issues. I looked on Thingiverse for a spool holder, but found they required parts that I didn't already have kicking arou