I asked whether or not a robot could lift itself on the field perimeter and, if I interpreted Karthik’s answer properly, I was told such a move would be illegal.
So I guess your self-lifting system would probably need to find something to suspend it besides the field perimeter or any other field elements. Of course you can lift yourself, but no part of your robot can be below the low or high plane when the buzzer sounds.
EDIT: um, uh… well it looks like my interpretation of my answered question was wrong as there was recently another question posted whose answer seems to indicate a robot can elevate itself.
[Answered: Updated: Previous Elevating Q&A clarifications - VRC > Nothing But Net (15/16) - VEX Forum
I sure hope Vex makes this issue crystal clear in their next rule update.](Answered: Updated: Previous Elevating Q&A clarifications - VRC > Nothing But Net (15/16) - VEX Forum)