This knob / thumbdial / thumbwheel is designed for the Alfawise U20 / U30 heatbed.
Other models here on Thingiverse (for the CR-10) are designed for different knobs and don't work with the Alfawise U20 / U30.
This upgrade is designed to include the 18 teeth original adjusting knobs. You don't need to scale it, tolerances are already good. I tried to make it printable as fast as possible, it will take 1,5/2 hours to finish.
Update | Added a smaller variant because the original one was too big for the Alfawise U30.
BUY - Alfawise U20 3D printer
BUY - Alfawise U30 3D printer
LEARN MORE - If you own an Alfawise U20, I strongly suggest you to buy TL-smoothers to fix the salmon skin issue
DOWNLOAD - Filament guide upgrade designed by me