This is a mount for an Ender 3 style printer to hold a cheap runout sensor from AliExpress. ($1.50)

https://www.aliexpress.us/item/2251832780928351.html

My runout sensor seems to be a bit different that the other ones, so the other designs did not work for me.

Use 20mm M3 bolts to hold the sensor in place and a couple of M4 bolts and t-nuts to attach to frame.

The mount is designed to be able to rotate to accommodate the angle of filament for a direct drive extruder.

Print with no supports.