The building instructions for Dicke Bertha Typ II were published by Matthias. From the web site:

The Ball Gun Dicke Bertha Typ II (German for: Big Bertha Mark II) is an enhanced version of Dicke Bertha, a NXT driven gun for the Blue Ball contained in the NXT kit.
It additionally features a second motor for the firing mechanism, a (detachable) magazine for four balls and a rotating Ultrasonic sensor for target detection.
To propel the five motors required, Dicke Bertha Typ II is controlled by two NXT bricks that communicate via Bluetooth.

You can find the instructions on the website and in our repository item for Dicke Bertha Typ II.