I've been tweaking this for along time, just thought I would send it out and let others give it a try. It is designed for use with Maxiwatt hot end, Haden Magnetic Arms, 50mm fans

Print Duct with ABS, the rest can be printed with PLA, the effector and carriages use 4 perimeters and high infill for stiffness.

I have included the .step files, so remix to suit your needs.