In case you missed it, on his Brickshelf folder, Netbulli/HUNLac5 posted 20 pictures and a video of this Lego Power Functions tank: http://www.brickshel...ry.cgi?f=321128 . He describes it as a "PF Tank, torsion suspension, working gun with a max range of 11m. Used 6 motors [two Lego RC "Buggy" motors and 4 PF motors]. See gun folder for further images about the gun." It shoots 6L or 8L Technic axles at a velocity of 12.5 meters per second. The YouTube video shows the gun in operation; there's even a quickie MATH LESSON to keep things educational and fun!