# Calibration of Z axis in Simplify 3D

I'm using Simplify3d and a DIY 3D printer. The printer works fine and I've printed very nice objects with very smooth and beautiful surfaces BUT they are twice as tall as they should be! It is like they're scaled double in Z axis! I've checked everything, I changed steps/mm from 4000 to 2000 but it ruined the smooth surface. changing layer height just makes smoother surface and doesn't solve the problem. What am I missing in the settings?

• Please add photos of the prints.
– 0scar
Dec 29 '18 at 0:09

Please re-calibrate your machine Z axis in firmware (most firmwares allow command M92 to set the steps per mm), not in Simplify3d, and then the extruder.