This is my working version of a spool holder. it uses bearings from a Traxxas RC car and linear rods from a Prusa 3d printer. Bearings below. you need 4 of the spool piece of and 2 of the end caps.

https://www.amazon.com/gp/product/B00ZVBREP2/ref=oh\_aui\_search\_asin\_title?ie=UTF8&psc=1

Print instructions

Category: 3D Printer Accessories Print Settings

Printer Brand: Prusa

Printer: i3 MK2.5

Rafts: No

Supports: No

Resolution: .2

Infill: 20%