G-code edits for all Elegoo printers

[cliffyk]

You are correct--the first motion of the platen the platen when starting a print job will be for it to ALWAYS descend to the limit switch controlled position--it has to so that the firmware will know where the true physical "0" position is. This makes the initial setup, alignment and adjustment, of the platen essential.

After that, when it receives a G-Code G0 or other "goto 0" command it will go to the "logical" 0 position established by the "Z=0" function (or as configured in the G-Code setup file). BTW I have never, with a properly adjusted platen--other than when experimenting to see what it does-- used or felt a need to use the "Z=0" function. Elegoo support initially described it to me as an adjunct procedure (a "time-saver") to be used if physical re-adjustment of the platen was inconvenient.

I believe that setting an M8084 value of other than Z0 (usually positive) in the stup G-Code does the same thing as usin the 'Z-0" function--however I have never validated this via experimentation. It would be interesting to load a setup file with M8084 set as "Z0", then align the platen and use the "Z=0' function to save a zero position offset, and next download the parameters and see if the M8084 value has changed. AS I stated above, I find the "Z=0" function to be superfluous with a properly adjusted platen.

But I think what you are saying is that in either case the Z height will begin printing in the proper spot *once calibrated* via M08084? Or am I missing something?

YES, with the caveat that it will ALWAYS travel to the physical, limit switch determined "zero" position first, an THEN rise tp the position established by the "Z=0" function or via the M8084 setup parameter.

I will not address the issue of "debris in the tank" as with a properly operated machine that is an impossible situation--the operator should always check the resin vat for debris and clear it if needed BEFORE printing.