Quite a lot of work here, although it doesn’t really show
First off, this is an early MKI lathe, I have a manual for a later model. That includes a handy screwcutting table featuring ratios of 1:2, 1:1 and 2:1 across the A-B spindles using a 30t, two 45t and a 60t wheel. I didn’t have the 60t wheels, so I made a pair. I then found that they wouldn’t fit – the distance between the A and B spindles was too small. So, I removed the B spindle from the lathe base, machined off the spindle, drilled the hub offset and fitted a new spindle
At the same time, I parted the wheels off the back of the B and C hubs and bored them out to 7/8″. I turned the back of the B hub down to 7/8, fitted a drive pin and put it onto the C spindle. I made a new hub for the B spindle and could now fit the 52:44 gear pair for metric gear cutting
The next round of fun was fitting the drive to the quick change box. I decided to stick with the changewheel set up to give more versatility
The the tumbler reverse gears went. The banjo had been repaired before, it was this that failed, taking a bunch of teeth with it.
Fortunately, I had the banjo and tumbler gears from the MKII that came with the gearbox. I fitted this, then had another crunch when one of the spindles seized onto the gear
Eventually… I made a new steel 30t wheel for the sliding gear hub, and bored the hub for needle roller bearings:
The tumbler reverse wheels were also bored for needle rollers:
Those knurled nuts on the ABCD shafts are a nuisance, they come undone and the wheel falls off!