1.5" to 2-1/8 plug for drilling out larger hole for new deadbolt

thingiverse

So while doorknobs come in standard sizes, old deadbolts from twenty years ago required a 1-1/2" hole, whereas new ones use a 2-1/8" hole. I could drill a 1-1/2" plug out of a piece of wood and then try pounding it into the existing hole.. Or I could design a plug that can be 3D printed from any desired material, hammer it in, and voila! You have a nice concentric hole from the original position. I recommend printing two plugs, one for each side, as most cutters won't go all the way through the door.