Gravity 3 was the first one I saw - it was the one that appeared in Robot Wars Series 7 and flipped Dantomkia out in six seconds. It was also in the House Robot Rebellion with Behemoth, where it got the puncture you mentioned Adrian.

If you go on WJs profile and click on the madscience.tk web address theres pictures there of the versions of Gravity that came before no.3