top 10mm SHOULD be fine (as there is new gen nasty axes coming) as it has been in the past but not sure now. Base Depends on how structural it is, some bots it is just there to stop debris from getting in. Side and back (back could be 12 can't remember) on Blacksmith where 15mm and the only issue i was some bolts pulling through (Binky for you) and drumroll taking a nibble. Look at my new bot Forge Master for the damage report of Blacksmith at Manchester