Your MakerBot Replicator will shake during printing if you print at high speeds with acceleration turned off.
Attempting to print at high speeds with acceleration turned off can harm your MakerBot Replicator.
To check and change the Acceleration setting, go to the LCD menu on your Replicator MakerBot 2X and navigate to Info and Settings > General Settings > Accelerate.
You can turn acceleration off and on. Acceleration is turned on by default. If you have acceleration turned off, you should not print at speeds above 40 mm/s.