All gears in a set have to have the same diametral pitch to match up.
The center idler gear moves around to accommodate different gear sizes and to set your tooth clearance.
Someone did the research for me as there were too many combinations that weren't on the chart.
I cant eve begin to count all of the TPI this contraption will cut.
But still no 2 treads per inch the smallest is 3.2 threads per inch.
I new how to set the gears up for this I had no idea what the treads per inch would be.
https://www.google.com/url?sa=t&rct=...AoySUCKVJabZIw