Check that the screws holding the tips are firmly tight.
Power tools and accessories vary in quality and some may have wobble at maximum speed. Some tool brands do not have RPM markings on their dials so for safety across all brands you should test with your tool on two-thirds speed first and slowly increase towards full speed. If you feel wobble at any time you should reduce speed until the wobble is gone and treat that as your tool’s maximum speed. These RPM instructions supersede all previous RPM instructions that may have come with your Nibbler.
20000 RPM MINIMUM
35000 RPM MAXIMUM
You can access videos for the above instructions here: