I have done engravings with this at 16000 mm/min with no problems. lines started to not match up when in line mode. turned out the set screws in the pulley for the y axis stepper motor from factor were not tight. I tightened it back up which fixed the line not matching issue, but when you fill at higher speeds you get e checkered pattern. This was not a problem til now . Waiting for a response from ortur. Help The nice engrave to the Left , Day of the dead picture was created at 16000mm/min prior to this
UPDATE. ITHINK I HAVE RESOVLED THE ISSUE. FIXED BY UPDATING THE FIRMWARE