I have Anet A8 where I have changed the controller from the original to RAMPS 1.4 running Marlin 1.1.1 and ran into some strange issues with my Z axis.
Doing calibration (10 mm cube, 10x10x20 mm, 10x10x30 mm) I am dead on the mm on the Z axis. (10 mm, 20 mm, 30 mm) But when I print a part that is supposed to be 24 mm high, it comes out 27 mm high.
Went back to print calibration 10x10x30, and Z axis is dead on 30 mm again.
Also printed a bracket that was supposed to be 240 mm high, ended up close to 270 mm.
I am doing the same layer heights for all the prints (calibration cubes and otherwise). Starting with a 0.2 mm first layer and then 0.1 mm on all other layers. Using RepetierHost v. 1.6.2 with Slic3r v. 1.2.9
Anyone experienced something like this?