Barry, there is a gear train from the lead screw to the drive, the backgear is to reduce the drive speed only for threading and the like. One is independent of the other completely.

harbor Freight lists its lathes by SKU number, #44859 is the designation, and if you go to their website, you can see the manual that goes with it.

https://manuals.harborfreight.com/ma...4999/44859.pdf

The gear train is rather different from what's shown in the program, and I have both here, the program in my laptop AND the app on my smartphone, not like I haven't spent enough time reading the instructions.