here's a couple of videos of the speed reducer
I also have a reverse tumbler gear set I designed and built for this lathe. using small engine timing gears.
this speed reducer is built from casting and again small engine gears. the odd shape is due to making it clear the pulleys/gears on the lathe, which I then had to do a last minute change, seems the 2 drive belts interfered with each other so I had to rotate the assembly to keep the belts from rubbing.
I should add that when not in use I remove the speed reducer. It is held on by one 3/8" bolt so it goes on and comes off easily. The torque at the spindle is very high if you accidentally got caught by the work or chuck its going to be a very slow and painful experience. If you do this modification with the spindle running slow DO NOT get careless.