Moves the Z-motors up 40 mm, so you can move the z-couplings to the upper side of the printer top. Now I can print up to 100 mm height.Edit: You only get an increase in Z if the first thing to collide with the X-axis is the z-couplings. This gave me 13 mm, from 87 to 100.Print two. Get 40 mm longer M5 threaded rods, and 40mm longer M3 screws for the z-motor mounts. Round/chamfer the corners on the z-couplings, so they can rotate freely in the z-height gainers.