Lance Abernethy, a maintenance engineer from Auckland, New Zealand, 3D printed a cordless drill that measures 0.67 inches (17mm) tall, 0.27 inches (7.5mm) wide, and 0.5 inches (13mm) long and holds a 0.02 inches (0.5mm) twist drill. Not happy with that, he is already working on a smaller version.
Lance told 3Dprint.com:
It took me 3 hours to solder and try and squeeze [all the parts] in. The wires kept breaking off when I was trying to connect them and it was a nightmare trying to hold them in place and try to not short the battery. I have seen claims of the world's smallest cordless drill and I know mine is smaller but it's not a confirmed claim.