Many of my designs require several tool changes. Most of my time seems to be spend setting the Z-height of each tool. Because of this I've decided to automate it as much as possible (without investing in a auto tool changer).

I'm working on making a tool height probe, and I would like to get some opinions of what direction I should go in. I can think of 2 simple ways to do this:

1. A metal "button" with a plunger spring (so the tool won't crash into is during deceleration) that's connected to an input pin. When the tool touches it the pin is pulled to ground. The advantage of this is it's simplicity. The disadvantage is the normally-open nature makes it not fail-safe.

2. A simple normally-closed momentary switch plunger switch.This is more electrically isolated from the frame and is fail-safe, but requires a switch that always brakes contact at the same exact point.

Does anyone have any experience/suggestions on which way I should go? Or am I going in the wrong direction with both of these methods?

The next step will be writing a tool change macro for Mach 3, but I think I can handle that. I have programming experience, just not a log of CNC experience.

Thanks in advance,
Chris Esser