Hi all, I've spent about 3 very interesting hours browsing the boards hoping for an answer to my problem.
I have just upgraded to Marlin 1.1.4, put all my machine's peculiarities in the right places - I thought - went to the printer, auto-homed OK, great let's test print a Benchy.
Press the print button, printer heats up OK, does it's little homing dance and starts to print about 3 centimeters above the bed. Of course I go straight to the config.h file, that looks OK, next option 3dprintboard.
There seem to be one or two people who have had a similar problem over the years, but there hasn't been much in the way of help posted so either they threw their printer out of the window or they solved it and didn't tell anyone.
Anyway I'm hoping someone who has solved this problem or has some idea why it happens can help me. I can post a copy of my config.h and any other info wanted, if necessary.
By the way, for anyone starting down the Marlin Firmware upgrade route, I can thoroughly recommend the marlin-conf editor ( https://www.thingiverse.com/thing:2403436), it makes things much easier to see and understand.
Hictop 3DP-12 (Prusa i3 clone); Marlin 1.1.4;