Set fbx2edf to mesh. The edf file should be in the same folder as your .hmf and .tht files. You also have to open up the hmf and tht files and add your object to the list. This is what I do for any object with collision.
But something changed in an update and the ramps don't work as intended. Here is a link to a post I made about it.
But something changed in an update and the ramps don't work as intended. Here is a link to a post I made about it.