Ender 3 Bed Leveling Lock Knob

thingiverse

This is a simple knob that fits onto the same rods as the standard bed adjustment knobs found on Ender 3 and Ender 3 Pro printers. They are designed to act as lock knobs, which are tightened against the stock knob to prevent it from coming loose due to vibration during printing. I experienced a severe failure on my Ender 3 Pro that resulted in significant damage because the knobs came loose during a print, but these knobs have completely solved the problem. After using them, I've had to re-level the bed for over 50 hours of uninterrupted printing. The inner diameter of the knob is precisely 3.242mm, which is the minimum minor diameter required for M4x0.7 thread. A basic tap should be sufficient to create the threading, whether it's a T-handle or drill, as long as you're careful and go slowly. It's essential to have at least three walls of material on the inner diameter so that there's plenty left when tapping is complete.