Edited slicer modifications at the end.

This roller is made for the A1 mini, I personally have no idea if it would fit the A1, but the dimensions are taken from the spool holder of an A1 mini.

Disclaimer: Threads might turn out stringy, but they still work.

I made the threads on the tighter side, so they won't loosen from the printer's vibrations. Also, if you know how to tune the slicer in order for the print not to be stringy, please do so, and also let me know what you've changed, I'm still learning. If you leave the slicer as it is, the contraption will still work, but you might have to clean the threads a bit.

I printed this with 75mm/s inner walls and 300mm/s outer, I later printed other smaller threads for testing with the default speeds (200 inner, 300 outer) and they turned out way better, change settings at your own risk.

Also, installation is pretty difficult, but not impossible. Here are the steps I followed:

• Detach the spool holder from the printer.

• Insert the male-thread and place the first 8 rollers inside it, then push the thread towards the holder's arm, to hold all rollers.

• Now comes the hard part: while holding the male-thread, balance the remaining 8 rollers on the edge of the holder's end.

• With great balance and patience, insert female-thread over the rollers and screw the threads in tightly.

Suggestion for better quality threads in slicer (NOT TESTED ON THIS OBJECT)

Have Advanced Options turned on

• Quality

  • Advanced → Order of walls → inner wall/outer wall/inner wall

• Strenght (Leave everything as default)

• Speed (Leave everything as default)

• Support (Leave everything as default)

• Others

  • Bed adhesion → Brim type → No brim

  • Prime Tower

    • Ribwall (Off)

    • Infill gap → 100%

These settings have worked well for similar threads.