I bought a dial indicator from Harbor freight to precisely set the z height of the 2nd extruder on a JGmaker artist-D pro. I made a base to hold the indicator upside down so I can indicate the nozzles. (ie set indicator to zero on E1 then adjust E2 to zero)

Then I made a simple light duty c-clamp to mount the indicator to the hot end so I can tram the bed.

Print the screws at 95% scale in X and Y. 100% scale in Z and 100% infill

JGmaker Artist-D pro

No

No

.15

10, 100% screws