I’ve wanted to get Ryan’s Tiny Touch Plate since soon after assembling my Lowrider 2 a couple of years back. Unfortunately it’s such a good deal that the plate costs a fraction of the cost of shipping so I could never click the buy button.
But I’ve finally made one after Ryan suggested they were easy to put together. He was right!
Here’s the vid:
Very nicely done. Shows a lot of art and skill with video tools.
The video has the default coding for a z probe, which sets z=0 in machine coordinates.
I’ve since modified it as per this conversation.
Basically, It finds the top of the touchplate and I set z=0 in workpiece space. Touchplate is the larger bolt head from the end of the video.
Macro is now:
G53 G38.2 Z-57 ; Probe Z
G92 Z7.9 ; Set current offset to 7.9mm for Z
G0 Z20 F480
Changes to the firmware:
uncomment
#define G38_PROBE_TARGET
in Configuration_adv.h
and
comment:
#error “Z_SAFE_HOMING is recommended when homing with a probe. Enable Z_SAFE_HOMING or comment out this line to continue.”
in Warnings.cpp
G38.2 probes down once and stops when it hits the touch plate and DOES NOT SET Z TO 0 AUTOMATICALLY.
As per @jamiek 's advice: You can enable the same double-touch as G28 by enabling MULTIPLE_PROBING in Configuration.h
This whole tool is not necessary. I’ve done 2 years without it! But it’s really nice to have and makes the machine feel young again 
Great, thanks for the tip