Threaded Hole Remix of Best CR-10/Ender-3 Extruder

Remixed from CrazyPonkeyMen's "Best CR-10/Ender-3 MK8/MK10 Extruder for any (including flex) material"
Some people in the comments (and me) experienced some trouble getting the coupling to stay tightly. I simply threaded the hole to a standard M6 thread.