Consider how the object was oriented on the bed while it was being printed.
Is the offset directly toward or directly opposite one of the towers?
Offsets are the result of lost motion or steps. If the offset is aligned with one tower, that is the first place to look. A loose belt or loose pulley is the most likely cause.
If everything looked really good for many layers, then suddenly offsets, the problem may be the sleeved wires/tube snagging on an arm after the head reaches a critical height.
Have you tried printing this part more than once? Did it fail the same way each time? Observing it as the failure occurs can be valuable in determining the cause. Unusual sounds or sudden jerky motion are important clues.
"Trust no quote from the Internet." - Abraham Lincoln
i've printed it 2 more times. and it didn't fail at the same time.
also when it happens the nozzle is hitting the object.
so i think the nozzle lowers a bit, but i don't know why.
. after a hour of printing this happens. you see it at the pictures.