If you look inside the door of the lathe where the gears are you will see a chart .
The gear train diagram will help yo identify what gear is what , the first two lines on the chart are for the gearing for turning .
The gear train is identified by letters - m, n, a, b, c, d. With m being the gear that feeds out of the lathe head and d feeds the lead screw .
I have mine set for 0.100 mm per turn of the spindle which is the finer of the two feeds available .
Gearing is as follows :
M = 24
N= 60
A= 24
B=50
C=25
D=48
Once you have that set up if you want the coarse feed ( 0.200mm per turn of the spindle ) you change M to 28 and N to35 and leave the rest as is .
I was told by the person i bought my AL320 off that one of the charts had an error for thread gearing but i can't remember if it was the one in the book or the chart on the lathe .
Hope that helps !
Ian.