Posted by Bill S on October 21, 2004 at 08:15:58:
In Reply to: how should the finished product look? posted by Ray on October 20, 2004 at 20:04:04:
Hobbing leaves tooling "cups" in the bottom or root of the tooth when the table feed is great enough. These get smaller and less pronounced as the table feed is reduced. These don't cause any problem that I am aware of.
Sides of the teeth will show straight lines if the fixturing and the machine itself is rigid and tight. If you see random marks on the side, suspect some play or backlash in the machine or in the way the workpiece is fixtured.
If you see the same cupping pattern in the top land of the tooth, that is normal for a topping cutter. Using a topping cutter requires leaving some stock on the blank's OD. If you see cupping on the top land and you're not using a topping cutter, likely you're cutting way too deep. Try measuring over wires or measuring tooth thickness to be sure.
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