Hex Tool Handles

So I needed a method of holding a longshanked hex nut driver in a stub handle, to be able to get under the printhead of my original Prusa i3 MK3 and be able to remove & change the nozzle on the hotend - without having to go out and buy a (costly!) dedicated tool for the job.

Rather than print the whole handle with a high-density infill (with asssociated extra filament cost), the best alternative was to produce a couple of different-length handles with interchangeable bit holders, which themse