Page:Practical Treatise on Milling and Milling Machines.djvu/179

Rh Cutting a Worm Thread, Using Rack Cutting Attachment

Another use of the rack cutting attachment on a universal milling machine is illustrated in this operation. It is especially serviceable for cutting short lead spiral gears, when the angle is such that they cannot be cut on the milling machine in the usual way. An advantage of the rack cutting attachment over the vertical spindle milling attachment for this purpose is that the work of smaller diameter can be accomodated, or a smaller cutter can be used.

The cutting is done on the top of the work, and oil may be led to the cutter from the can shown.