looked at a few available spool rollers and holders, they either took too long to print or used hardware that is not easily available to me, this was the simplest working design I could put together. 

Required Hardware

• 4x 100mm 2020 Profiles

• 4x 200mm 2020 Profiles

• Corner connectors and nut/bolts of your preference

• 1x Bike Front Axle Rod

• 4x 6301 Bearings

• 4x M5 T Nuts with 8mm Bolts

The basic layout of the 2020 frame is flexible, and can be expanded to include multiple spools depending on the rod length and profiles sizes used.  

I used an off the shelf 12mm Bike Axle rod with 4x 6301 Bearings that I picked up at a local bike repair shop, the rod length should be a little over 145mm to fit the hardware listed above. 

Print 2 of the spool roller parts,  Adjust tolerances for your printer so that the bearings fit snugly in the holes. 

Adjust the height of the "rod mounts" so the spool is centered in height of  the frame.