Looks to me like you’re losing some steps in the X direction. Could be an issue with loose/tight belts, loose pulleys, low/high pots, or a number of other things. A couple quick things to check are belt alignment (make sure belts are in the middle of pulleys and roller wheels) and pulley set screws (make sure both are tight and one is seated firmly in the flat on the shaft).
I’ve made videos covering belt tension and potentiometer adjustments and posted them at X-Carve Maintenance/Troubleshooting Videos - Add Your Own!. They may help you think the tension or pots could be giving problems. First time use is always a matter of dialing-in the X–Carve, but it shouldn’t take you long to get that bowl perfectly carved. 