The Bar is held on by two nuts, tightened to the tightest that the word tight could possibly mean...
Bashing the whole weapon assembly, (and the rest of the bot) with a hammer, can not cause any problems anywhere around the bot, and YES I can stand on the weapon motor (hard to balance) without any base distortion etc... I have just fixed the titanium wedges that I will use for the weapon at the event.
Cheers, Ewan