Transform: How to rotate stl about a given axis?

I have a vtk showing a particle model of a screw being twisted. I tried to insert an stl file for a screwdriver in the correct position and tried rotating it at the same rate as my vtk file. I added a Filter->Transform->Rotation(2) about z-axis, and added the final angle on the animation panel. I assumed the rotation would occur about the center of the stl itself but the stl started spinning about an unknown axis instead.

  1. How do I figure out which axis the stl is moving about?
  2. How do I make it rotate about a specific axis?

It is rotating around the origin.

How do I make it rotate about a specific axis?

You want to use RotateAroundPoint mode in Transfrom filter. Available in the nightlies.

I tried to change the origin in the transform filter but it doesn’t seem to be working.
Could you perhaps send a screenshot to indicate how to use the RotateAroundPoint mode?

Sorry, not in 5.9.1 but present in the nightly, you can download it here:

Filter → Transform
In the combo box, instead of transform choose RotateAroundOriginTransform