The mini lathe has a gear in position A linked thru an idler gear to spindle.
This lets you change A/B ratio easy, you can also reverse the lead screw rotation as well with a lever to engage a forward or reverse idler gear.
The 8x16 doesn’t have this option, lead screw follows the spindle.
May be possible to add a gear to reverse lead screw for left hand threads but I haven’t tried it yet.
28.015 is 28tpi. Keep in mind .015 is not 15 thousands.
It’s .015 of width of 1 thread, slop and improper depth of cut can cause out of spec threads way more then the .015 of a single thread due to gears.
More experienced lathe operators will know more and can pass on if this is an issue, but that’s how I see it.
For old lathes such as Southbends or Atlas 618, etc, a reverse gear set with
handle is supplied. Allows for left hand threading ...start from head stock to tail stock.
e.g.,SOUTH BEND LATHE 9 INCH REVERSE GEAR TUMBLER WITH GEARS AND LOCK BOLT
<< https://www.ebay.com/itm/SOUTH-BEND-LAT ... :rk:4:pf:0
Also most useful for winding springs. At your leisure lots of YouTube on spring winding.
One of best is winding a 'double-mouse-trap' spring for an old WW2 piece.
Tubalcain YouTube instructional videos a good set of tutorials.
Welcome to Metal-Mania ... tool junkies anonymous ... 'Toad from 'Wind In The Willows
wide eyed excitement. Someone once said that tool companies could give the lathes
away because the tools that 'you must have' every time a new MSC or
McMaster-Carr catalog is delivered will bring in revenue 10 times the cost of lathe.
Happy chip making.