ONLY FOR LEGACY MODELS USING REV F PRINTRBOARDS
This version is intended only to support legacy (~early 2014 and prior) model Printrbots, usually those without the inductive "autolevel" probe, which home toward Y=0.
This version is NOT to be used on current shipping Printrbots (Metal Plus, Metal Simple, Play) as it would attempt to home in a direction where there is no endstop switch. Noise and/or damage may occur!
Note that this version does have the "auto-level" feature enabled, in support of legacy users who have retrofitted the inductive probe.