MX600 lathe change gear kit

The MX 600A lathe has lackluster options for cutting imperial threads. The spindle thru bore is larger than the normal 7" mini lathes and the spindle output gear is a 56 tooth vs a 40 tooth. I designed a gear rack (banjo) that is 25mm (1") longer than stock to accommodate the larger gears.

The gear drive train goes from the spindle 56 tooth to a 56 tooth on the top gear shaft. This gives us an easy 1:1 ratio to work with. The 50 it is mated to drives a 100 tooth to half the speed. The 127 is on the same shaft as the 100. The 127 does the metric to imperial conversion going to the lead screw gear. The nice part of this setup is the top two gears can stay on the rack and only change the bottom gear at the lead screw and readjust gear mesh.

The MX600A has the gearbox where Medium is 1:1 ratio, Low is 1:2 and high is 2:1. Plus it can change leadscrew rotation to allow threading toward or away from the chuck. This allows the 9 gears that go on the lead screw cover 8-44 TPI. The ge