Applications for a CNC lathe | Gear Hobbing

Gears are a key component in engineering, their production has always been considered complex and expensive due to the initial investment required to purchase a gearing machine plus the technical know-how related to it. However, it is also possible to do gear hobbing in a CNC lathe. Hobbing is a process to manufacture gears by the use of a tool known as “hob”.

The geometry of the gear in the gear hobbing process is obtained by the synchronised movement between the spindle and the live tool. The limit to manufacture gears in a CMZ CNC lathe is around the hob tool being able to produce the required profile but for occasional machining. Bigger gears require bigger tooth depth and the time required to manufacture them would be too long, as the torque of the machine would not be enough at low rotation of the live tool.

Gear machining on a CNC lathe through hobbing requires a special live toolholder to mount the hob.
Y axis is not mandatory but will allow the use of the whole length of the tool as once it is worn it can be shifted to machine in a different Y position.

Gear hobbing allows both machining straight and helical gears as well as splines. Gear hobbing is limited to external machining.

This document will guide you through all the basic gear parameters and the cycles required to machine gears on any of our CMZ series CNC lathes.