Creality Ender 3 V3 bed leveling knob replacement
A replacement thumbwheel for the bed leveling screws on a Creality Ender 3 V3 SE and KE, Ender 3 V2 and Neo, which use M4 screws with a knurled 34 mm plastic knob that cracks after a few rotations. The wheel is 40 mm in diameter and 10 mm tall with twelve 2 mm scallops around the edge for grip, a pocket for an M4 square nut 7 by 7 by 3.2 mm pressed in from the top with 0.1 mm interference, and a 1 mm chamfer underneath so it clears the bed spring. Print it face down in PETG or ABS at 100 percent infill; the nut pocket needs no supports.
Oversized knobs give finer control than the tiny originals, but only if the nut pocket matches your screw. In SpeakCAD you name your Ender model, preview the wheel in the browser without paying, add a hex pocket for an M3 nut in the chat, and download the STL.
Design a bed leveling knob 40 mm in diameter and 10 mm tall with twelve 2 mm deep scallops around the rim, a central 7 by 7 by 3.2 mm square nut pocket from the top with 0.1 mm interference, a 4.5 mm through hole, a 1 mm bottom chamfer and a 0.5 mm raised arrow on the top face.