Going senile or is this really not possible...

[mhackney]

Ok, so I have a perfectly calibrated Rostock Max. It is setup with FSRs for probing. Every day I start up and print a single layer test print. Most of the time everything is fine and I'm ready to go. Sometimes the test print is a bit too thin or thick so my Z height needs adjusting. Today, I open the eeprom dialog and tweak the Z Max Length parameter a bit to compensate. It would seem to make sense that there would be a G or M code that does this (Repetier firmware) but I haven't found it. Basically, home the printer, probe down and when it touches off, set Z=0 to that length. Any ideas or is this really not supported?

[JFettig]

I don't have the answer to the question biut temperature change greatly effects the z zero on these machines since the rils are so long. I usually have to adjust for my second print with a heated chamber. Also the limit switches are not 100% perfect.

For most of my prints, I don't care what the first layer looks like as long as it doesn't kick stuff up and it sticks so I print it taller and 80% extrusion width. It's not 100% filled in and it compensates for rail growth.

[mhackney]

True. I allow my print bed to come up to temp for 30 minutes to equilibrate. It is surprisingly stable but does need the occasional tweak to set Z=0. For me, the first layer is critical since it is visible on the fly fishing reels I print & sell. I also print on PEI so too thin of a 1st layer is a bear to remove.

I basically have things exactly the way I want them. Everything is stable and repeatable and I print 6+ hours continuous every day. This one little thing just irks me though! With FSRs on my machine, it should be dead simple to just say "set my Z=0 for me" after the bed is at temp and stable and be done with it!