623 Bearing Arm for DieselG's Thing

Changes made to "bearing arm":
1) Made to fit the cheaper 623 bearing (about $1 on ebay)
2) Extended the arm by a few mm's (to make up for the smaller bearing OD)
3) Made the bearing axis fit a 3mmx10 set screw/bolt
4) Combined the two halves
5) Deleted the tabs