New effector system.

Uses V-rail, 623 bearings, and mostly m3 hardware.  Currently untested.

Rough BOM, per tower
4 rod ends
8 10mm m3 screws (clamp rod)
8 20mm m3 screws
16 m3 nuts

2 bearing bars
6 623 bearings

4 2mm long m3 spacers (mcmaster-carr)

rail effector
4 v-wheel assemblies (openbuilds part store)
2 eccentric spacers

2 20mm m5 screws (for belts)
2 m5 nuts

hotend effector (well, 1/3 of one).