I bought a power screwdriver to undo screws on avionics, simply because there were 84 screws holding the case lids on. Took a hex key of 2.5mm and brazed the long end into a brass hex standoff ( it was a perfect fit in the driver 1/4 hex holder) and over time it got shorter by 3mm each time it wore too much. I wore out a gearbox in that driver, and had to replace the 2 NiCd cells as well, but that was when Black and Decker still made good stuff, and had spares support as well for them. Off was power, and on was a hex key for the first turn then use the power to get close to tight then finish off with hand turning the driver. Never stripped a screw except for those I had never removed that had been monkeyed in before. then I learned how to use a recoil kit, and did not have to drill or tap as the original screws were all done with inserts from manufacture.