Hi everyone,
I scoured the internet trying to find good Mach 3 auto-probing macros to no avail, so I found one that was close and went from there. This macro was developed on an OMIOCNC X8-2200-USB, but it should work just fine on most other routers. I finally was motived enough to find and develop a macro after fighting with multiple tool changes and failed cuts, so hopefully, my pain is your gain!
This macro should allow you to swap tools on routers with ER20 (or similar) collets without measuring tool lengths! Give it a try and let me know if it works for you.
https://github.com/juchong/mach3_manual_tool_change_macro
Enjoy!