Hello.
Upgrading my ultimaker with a heated bed made me use branch Marlin_UM_HeatedBedUpgrade.
After some bad (z-compressed) prints i figured out the problem:
looking into Configuration.h where DEFAULT_AXIS_STEPS_PER_UNIT is defined i find the following:
#define DEFAULT_AXIS_STEPS_PER_UNIT {78.7402,78.7402,200.0,760*1.1}
steps per unit for z-axis: 200
while in branch "Marlin_v1" i find a different value for the z-axis:
200.0*8/3
which explains the "compressed" prints and my bent heated aluminium bed...
changing that value solved the problem.
The same value for the z-axis (200) is to