Sources for Imperial Knight Magaera Volkite Carronade 

Dominion Crusader chassis (28mm) MK3 (http://www.thingiverse.com/thing:2997180)
Dominion Crusader MK3 Tartar Armour (28mm) (http://www.thingiverse.com/thing:3364519)
Renegade Knight Sonic Cannon (http://www.thingiverse.com/thing:3383858)
