In regards to choosing a lapidary saw, a 4" saw limits you to only
cutting small pieces of rough. I have a 5" and it is pretty
limiting. If you only cut slabs, if you plan to cut something over
2"long, you need a saw where the part that holds the blade is below
the table so you can run the slab through with hitting that part.
My raytech is not that way, so I can only cut 2.5" deep unless I
hold it above the arbor.