X carve problem cutting x axis failing on -x

Hi…i hope someone can help me with this. I have the x-carve 2015 model of 1000mm. I start to have a problem cuting a piece that is almost a rectangle i used a whiteside ud2020 1/4" compression bit for cutting 3/4" melamine chipboard. everything is running ok until the cut stars on -x it sees to loose some steps or something because it does not meet with the start point by a 1.2mm difference each pass. i already calibrated the steps on the machine, readjusted every bolt and nut put some locktie where is needed. analyzed the g-code to see if is not a problem there, but nothing. i’m using Vectric Apire with the Xcarve mm Post processor.

thanks in advance

Possible to share the project/gcode?
Otherwise we’ll be randomly “guessing” :slight_smile:

I just added the g code of the piece im trying to make.

Power Cover.gcode (14.7 KB)

i just added the file, thanks for your answer