G33, am I missing something ?

So, the long and short of it, I have an anycubic delta with a bltouch probe attached running marlin 1.1.6 (geting 1.1.6 on was fun thanks to a bodge in the official anycubic releases!), i've compiled in support for auto calibration and it seems to run ok, afterwards it returns to home position, if I then issue G1Z3 and slowly edge it down it hits the bed at 2.3mm every single time!
At first I thought this was just the z probe offset as I was still tweaking this, so I adjust it accordingly and got the same result, i've since tried adjusting it to silly figures, and even changed direction, same result and regardless of what I set the offset too the z height is always 331.6 mm.

So either i'm doing something stupid (and is usually the case, very obvious), or something very odd is going on... hopefully someone will be able to tell me which it is

It looks like you made the change to the z-offset in the FW and:
- did not load the default FW settings into memory M502 neither saved them into EEPROM M500
or
- did not recalibrate with G33 after re-flashing the FW

Change the z-offset with M851 Zx.xx and check if your changes to z-offset have taken effect with M503; safe with M500 and only at the end hardcode the z-value in the FW.

the hard way:

- make the change in the FW
- recompile and re-flash
- start printer (and load calibration settings from EEPROM into mem)
- M502 (load FW settings into mem and override EEPROM)
- M503 (check if everything is OK)
- G33 (recalibrate since calibration was lost)
- G1 Z3
... until OK
- M500 (save mem to EEPROM for startup)

the easy way

- start printer (and load calibration settings from EEPROM)
- M851 Zx.xx (change Z-offset in mem)
- M503 (check)
- G1 Z3
... until OK
- M500 (store mem to EEPROM for startup)
- make the changes in the FW for future ref
- recompile and re-flash (so future M502 commands will have the right values)

Edited 1 time(s). Last edit at 10/23/2017 04:34AM by LVD.

I actually did save and reset the offset when flashing, hence my confusions.

I have been playing with using M851 which does work but no matter what I do when compiling it's ignored (wiping etc), thankfully setting it manually seems to actually work.

You have however confirmed that I was doing things correctly, I may check with m503 and see if perhaps the setting in configuration.h is simply not being moved over.

Quote
MiggyMan
I actually did save and reset the offset when flashing

Then you also did reset and save the delta height. Did you recalibrate after re-flashing?