Quote Originally Posted by Roxy View Post
If you don't trust the mechanic's of your printer, shouldn't you be doing a G29 before every print? And if that is true, why would you add this code to your firmware?
Nope, heat makes it flex and the parts expand and when it cools down, plus the movements of the bed while it is warm, makes the parts change ever so slightly.

To see if your printer will work do a G28/G29 U 6 T with everything heated up. Now go do a print of something like normal. Let it all cool down and in 1 hour come back to a nice room temp printer. Now with the complete printer sitting there at room temp go heat up the hotend and bed then do a g28/g29 U 6 T and see if the numbers are exactly the same. If they are then you have a golden printer and should never need to do another G28/G29 again.