A short screwdriver, with 7 interchangeable bits.I've been looking for an interchangeable bit screwdriver with the metric allen wrenches and such that I use on the printer for some time now, and hadn't found it.I found a 100 piece boxer power tool set at Fry's, for $16, which had all of the bits I needed in it, and a magnetic coupler, for use in an electric drill.With a printed handle, and some tiny magnets, I now have exactly the screwdriver I was looking for.Vitamins:     1 x Magnetic coupler for using interchangeable screwdriver bits in an electric drill.     7 x Various screwdriver bits.     6 x Small, round rare earth magnets (Mine were 1mm thick by 3mm diameter - the magnets must be smaller than the back ends of the screwdriver bits).Print the handle.Test fit the coupler and bits - use a needle file to adjust the sockets so that the bits have a loose fit (you want them to just be able to fall out), and the coupler has a slightly tight fit (still removable, if the set screw is loosened).Insert a nut into the nut trap, and a M3 setscrew into the nut.Mix up some 2 part epoxy - I used J-B weld.Grease the back ends of the screwdriver bits, so that the epoxy you'll be using in the next step won't stick.Center each magnet on the back end of a screwdriver bit, dip the magnet in epoxy (being careful to avoid getting any on the bit) and insert the bit into its socket, magnet first.Once all 6 bits are inserted, clamp the handle lightly in a vice, so that gravity will keep all of the bits in place, and let the epoxy set overnight.Install the magnetic coupler, and tighten the set screw.After mine was finished, I decided that it could be more comfortable, so I did some finish work on it. This method of finishing assumes that it was printed in ABS.Using a temperature controlled soldering iron set to 235c, use some of your scrap ABS welding rod to fill the top of the nut trap.Using a fine rasp, or diamond grit file, round off the welding, and smooth down the extrusion ridges.Smooth everything further using fine (600 grit) sandpaper.Smooth everything even further using very fine (2200 grit) sandpaper.Pour some acetone onto a clean paper towel, and give each surface of the handle a quick wipe - just enough to give it some shine. The goal here is to have the acetone evaporate from the plastic quickly, so a wet towel is good, while a soaking towel is not.Polish the surface against your jeans - or with a polishing wheel, if you insist ;-)