From the manual;
"The file lathe-test.cb in the CamBam samples folder demonstrates the new lathe operation.
In this initial lathe release there are a number of limitations:
Only profiling operations are currently supported. No facing, boring or threading support yet.
Apart from the tool radius, there is no mechanism to define a lathe tool shape. The part should be drawn to allow for the cutter size and shape."
Once CamBam is opened click on "Help" to bring up the manual, there is a section on using the lathe function and also sample files in, "Tools->Browse System Folder->Samples"