I've adapted Mtorromeo's Allen key to hex bit adapter to fit the pair of allen keys that comes with Bambulab's printers. They will fit 2mm and 1.5mm sized allen keys to easily fit into a standard hex bit for a small drill or screwdriver. The tolerances are quite tight to help prevent wobble at the end of the long allen key. This small print will make it easier to work on upgrading your beloved printer!