[Algirdas]

Depends.
Don't understand, why you want to involve Arduino here. Anyway, doesn't harm.
The sensor brass plate isolated eletrically from the body and +24V is connected to it through the action relay coil. The tool tip brings the body ( ground ) potential.
When the tooltip touches the brass plate, loop is closed and action relay activated. You have the signal and closed / open contact to stop fthe movement and whatever you want to.

[dwall174]

Don't understand, why you want to involve Arduino here. Anyway, doesn't harm.

I'm not really sure if I need the Arduino either that's why I'm checking into it.
I could probably get by with a simple touch light circuit like the one attached, But I would think the Arduino based touch off plate would be more accurate?

I know the Arduino's have been used like that before, At about 8 minutes into this YouTube video it shows sort of what I'm looking to do with just the touch off plate.

https://www.youtube.com/watch?v=QnPmQpd9rLw&t=3s

At this point I'm not looking to try to get the Arduino to display the height or control the motor.

For my router table I don't plan to use a CNC spindle like in the video, Mine will just be using a portable hand-held plunge router mounted up-side-down in the table.
To control the routers lifting I'll just be using a 24V DC gearmotor controlled with a simple PWM controller (pic attached).

Here's a little more information on how the Maker Barn connected their digital controls to the Arduino.
https://www.instructables.com/Digita...r-Router-Lift/

Doug

[dwall174]

Here's a YouTube video showing a Arduino & the KY-036 sensor controlling a relay board that turns a standard light-bulb on & off.
https://www.youtube.com/watch?v=xQxF8tKccgI

I figure it could also be used (and re-configured) to just switch off the 24V DC gearmotor when contact is made?

Doug

[dwall174]

Searching around on a little more I think maybe this standalone 5-pad capacitive touch sensor - AT42QT1070 & a relay board should work out ok with-out the Arduino?
https://www.youtube.com/watch?v=9zxGipGvLiw

Doug

[dwall174]

The sensor brass plate isolated electrically from the body and +24V is connected to it through the action relay coil. The tool tip brings the body ( ground ) potential.

The router motor is basically a modified hand-held power tool & it's double insulated so there's no ground connection. The motor will be off (DPDT Switch) during the tool zero set process, So there's no chance of a ground potential.

The power supply I'll be using is a switching power supply, So that will also help a potential ground problem.

Doug