Worm Drive Dividing Attachment for Mini Lathe

[old_toolmaker]

I had a need to divide a micrometer dial into 360 divisions so I built a worm drive dividing attachment to fit my 7 X 16 mini lathe. This design is a collection of ideas gleaned from the internet and re-engineered to suit me on my CAD system. (You know how we "Builder Types" always have a perceived need to improve things!)
It has an 8:1 ratio and the steel worm meshes with an idler gear (a plastic mini lathe change gear) which in turn drives the standard metal 45 tooth spindle gear. The index plate has three hole circles having 35, 40 and 45 holes With this arrangement it can index for most all divisions I am likely to need including 360 degrees which is why I built it in the first place. The worm is canted at an angle to better mesh with the plastic idler spur gear. A worm wheel would certainly be better than the plastic spur gear but for a low speed and seldom used device it works well enough.