Tachometer for HF / SIEG X2 mini-mill

This would surely work with other similar SIEG X2 minimills
Note : You have to remove the safety shield (at you own risk!)

Sensor & Housing:
I did not want to use a spinning a magnet glued to the shaft at 2500rpm. Who knows when that would let go! (Although if you made a thin cup like housing that bolts on top of the shaft maybe that would be safe) So the sensor I chose is an IR proximity sensor (Amazon, etc). These use 5vdc.
The sensor housing is held in place with two 4mmx12 screws tapped into the upper housing.
You have to notch the cap to fit over the sensor housing (easy job for dremel and a file)
I painted part of the shaft nut white as seen in photo to create the pulses. I bet a shiny reflective sticker would work too.
The housing keeps the IR sensor hooded about 10mm away from the shaft and that seems to work well. All you have to do is adjust the sensor sensitivity to what works best for you.
I used a plastic screw and nut to secure the sensor in the housing but you co