Designed to hold up the Y axis gantry when Cetus is powered off so that the nozzle doesn't rest on build plate. Stop works best in the four holes that our marked with red arrow in diagram but will work in the other holes that have socket caps in them.
V1 has centered pin to for easier alignment. V2 has offset pin to allow the use of the lowest hole V3 (Latest) has storage on side of Z gantry. Print with supports.
Inspired by Redonix76's simple Zaxis stop http://www.thingiverse.com/thing:2063886