I modeled this system to be able to grow and add more spools down the road. I designed the roller to be low friction on the wall mount, so the feeder doesn't struggle. I'm using 4mm/2.5mm tubing and it fits snug in the guides.

External Hardware:
-M3x4mm Thread Inserts (https://www.amazon.com/dp/B0DFGTC4KF?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1)
-M3x10mm Alloy Steel Hex Head Screws (https://www.amazon.com/dp/B019ZC3MD0?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_5)
-Drywall Screws