About this 3D model

A step drill is a handy tool to have beside your 3d printer. They are a bit hard to turn in your fingers and an electric drill is overkill for sizing a hole. This thing takes my step drill so I can turn it easily by hand. The hex shaft looks pretty standard so you can probably use screw driver bits in it. Or maybe you can use a hex drive extender with it. No doubt it has been done before. I'm posting two versions. One has a hex hole right through and the other has the hole blocked off. I added a screw hole to lock the bit in. My print was too tight but I put the PLA thing in hot water and the drill shaft slid in with no effort. It is stuck there now which is OK with me.