Page:Practical Treatise on Milling and Milling Machines.djvu/175

Rh Cutting Teeth in Spiral Gear, Using Compound Vertical Spindle Milling Attachment

This operation shows the use of a compound vertical spindle milling attachment in cutting a spiral gear.

It will be noticed that where this attachment is used, the swivel table is set at zero and the angle of the spiral obtained by swinging the head of the attachment. The cutting is also done on the side, instead of the top of the gear.

In cutting left-hand spirals, the cutter would be at the back of the blank, the head of the attachment swung to the other side of zero, and an intermediate gear would be introduced in the train to reverse the direction of rotation.