Squirrels love a nut. Airtrippers suck with a nut. I've never had mine pop off, but I have a hell of a time getting in new filament, so I have modified it to accept a threaded adapter for the bowden tube. This is derived from my other derived airtripper, and from the threaded bowden clamp posted by jamesarm97. This is not parametric, so if it doesn't fit for you, bust out the files or sandpaper.Print, assemble. The raised squares should line up. I considered adding a snap on the extruder housing against the adapter, but I don't think keeping it in place will be a concern. Fair warning: I haven't tried this yet. It might still need adjusting. I've printed two, and the pieces fit nice and snug, but my printer and I aren't getting along at the moment and she is making weak parts. The hotend adapter should accomodate a Jhead.... You might need to tweak the scale on the ring or cap.