This is a thumper assembly that is positioned in a developer station of a xerographic marking system. A waste container connected to a drop tube collects waste developer from this station. A magnet prevents magnetic developer from moving through the tube when the container is removed. Once a new container is installed, the magnet is moved away from the tube thereby allowing magnetic developer lodged therein to again move through the tube. A thumper is moved striking the tube to further dislodge developer and allow this developer to move through the tube into the waste container.