A simple spoolholder that clips onto the aluminium extrusion. Can be printed in under an hour with 0.3mm layer height and 20% infill. This should work with any misumi 20x20 aluminium extrusion as long as you can find a place for it where it wont interfere with the rest of the printers mechanics. As other extrusions might have more rounded edges i can say this will work for every type of 20mm extrusion, but feel free to try and post in the comments if it worked for you :)