Out of round circles and flat spots are normally caused by machine backlash or a mechanical issue. Depending on the machine it can be a bad ballnut/ballscrew, a loose drive belt, worn pinions or gear rack. It may also be linear rail bearings causing side to side movement as the machine changes direction. A good mechanical inspection and replacement of the bad parts will fix the issue.

Check the condition of your leveling feet. These have a tendency to rust up after several years and not function properly. I recommend replacing them with new ones before installing the machine at a new location. If the machine is traveling a long distance, remove the PC from the machine and transport it in the cab of the truck or by car. Have a qualified tech disassemble the machine to check for any other issues that may need attention.