I tried to print a 1inch long calibration on each axis. All of them have 1inch measurement. But, the vertical axis looks very distorted especially if the print area is small. Do anyone have any suggestions on resolving this issue? Thanks. I am using Ramps 1..4 with Marlin firmware.
It looks like your layers are too small and the part doesn't have enough time to cool off. Try directing a fan at the extruder. If you're using Slic3r, there is a cooling option that uses a pwm fan.
that's absolutely right, that problem is due to print time for each layer being too short, and the bottom layer couldn't cool down quick enough for the next layer, so the nozzle is pushing the lower level when moving above.