I designed a new docker piece using your STL file. Just like the receiver tool dock which has a flange separating the magnet from the surface, I put a similar 0.2mm flange in the plastic to keep the magnets separated. However, my printed docker pieces were never as precise as the E3D docker, so I am not using it. Too much wobble when docked. The good news is that I have redesigned my version of the Flex3Drive tool , replacing the flex cable with a tool mounted Nema 11 stepper motor. The stepper weighs around 190g, giving a final tool weight of 394g. This obviates the need for the enhanced force tool dock magnet, as the new design doesn't experience the off-axis forces from the Flex3Drive cable. I essentially made a 90 geared stepper using the Flex3Drive plastic worm gearset. I'll post it up as a new topic on the forum. I am VERY happy with the performance.