I made the mistake of buying a 3kg spool of Polymaker's PLA Pro, because I print A LOT in white. So much so that I have a whole machine dedicated to white. I THOUGHT it made a lot of sense to just buy the bigger roll and run out less. What I didn't consider was that the roll doesn't fit on the spool holder, AND even if you print a longer holder, the roll is too heavy and binds up the extruder. My options were to spool off smaller amounts onto old rolls, or design a better mount.
To make this work, you'll need some sort of spool adapter to go on the inside. Below is a link to printables for the one I used. You'll also need four 22mm bearings. I just used a cheap one off of amazon. I also used a M8x1.25 - 200mm long threaded rod, and 2 serrated flange nuts (M8x1.25 also). I'll post those links below also. You’ll also need four 5mm bolts and t-nuts
I also mounted a bowden connector mount in the middle of the spool mounts which keeps everything centered and moving well. That link is below also.
https://www.printables.com/model/601604-spool-hub-for-polymaker-with-bearings
https://www.amazon.com/dp/B003MW0GCA?psc=1&ref=ppx_yo2ov_dt_b_product_details
https://www.amazon.com/dp/B0BY7N18WD?psc=1&ref=ppx_yo2ov_dt_b_product_details
https://www.amazon.com/dp/B09PKD8QZZ?psc=1&ref=ppx_yo2ov_dt_b_product_details
https://www.thingiverse.com/thing:4235116
The author marked this model as their own original creation.