I designed this effector for my Ultibots Kossel 250. This effector raises the extruder just high enough to be used with 288mm arms and a 250mm bed. Currently the motor duct hits the top arms when on the edge of the build plate near the Z tower. Currently this is designed to be used with the E3DV6 hotend. I will include a version for Jhead when I get the time. The extruder body is the Ultibots version with Jhead slot since I got lazy and did not want to redesign the body. If anyone wants the cad files I would be happy to share them but they are in CatiaV5. In the future I plan on recessing the hot end up to the extruder, but I just don't have time currently. Also, you HAVE to use a PTFE tube or something like it. The motor fan duct and extruder body can be found at the Ultibots github: https://github.com/UltiBots/K250VS If you have any ideas or suggestions feel free to leave them in the comments =)