Biqu BX spool holder

Here's a nice ball-bearing spool holder for a Biqu BX. The standard thing is just a straight bit of plastic with a lot of friction, so I designed this to be a drop-in replacement.

You'll need about 15cm of 8mm threaded bar, and 3 or 4 M8 nuts, and 2 standard 608 ball bearings.

The original mounts through a 30mm hole in the steel support arm, and this mounts in that hole.