Instructions
Buy these brass bushings
mcmaster.com/#6391k163
or
If you want to be really adventurous
One of these two PTFE tubes (have not tried, but PTFE is inbound :)
mcmaster.com/#5033k34
mcmaster.com/#52335k38
Drill out to 8.2mm for good fit on 5/16 drill rod
coat in 2 part epoxy
insert in holder




