spindle speed pick-up using the bull gear

Hello folks,

Wondering if anyone has incorporated a hall effect sensor in their Bridgeport gear head to pick up real-time spindle RPM.

My plan is to drill and tap a hole to pick-up the bull gear teeth with a hall effect sensor, then wire the sensor into my encoder_4 inputs on a  mesa 7i77.
Is this is viable? If it is what I am looking for is measurements and locations on where to drill/tap the hole for the hall effect sensor, also what sensor do people use for this job? I currently have a ZF GS100502 gear tooth speed sensor good to 15khz.

I have the following hardware:
Bridgeport V2XT {1996) donor mill using the legacy servo motors and drives.
Mesa 7i92M and 7i77D
cheap amazon VFD.


Please advise.
John VanAtta
 

We used gear tooth sensors.... for rigid tapping you would need 3 - a,b and z

Jon from pico systems did the same thing...

pico-systems.com/bridge_spindle.html

Good writeup..

sam