DEC RL-02 Spindle Ground Brush

This is a replacement for the spindle ground brush used in the Digital Equipment RL-02 removable hard disk drive (circa late 70s).
These drives use a graphite brush which grounds the rotating spindle to the body of the drive. Graphite is somewhat uniquely suited for this task because it is electrically conductive and self-lubricating, avoiding the galling that would occur otherwise.
I have not been able to fashion a replacement yet (given I can't print graphite), but here is the 3d model of the brush.
More info on the RL-02:
http://www.cosam.org/computers/dec/rl02/
http://www.pdp-11.nl/peripherals/disk/rl-info.html