Relief angle....? None?!

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Hukshawn

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So I came across this puppy today.
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What strikes me as odd, is there's no relief angle on the carbide.
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It seems to cut nice, not a fan of the insert, but the complete lack of relief angle seems weird to me.
 
Neutral or negative rake cutter. Yes, it will cut just fine, but needs more power than a positive cutter. Neutral cutters are presented at 90 degrees to the work, with no back rake. Often those plain cutters are presented at a negative angle to the work on bigger and heavier machines, and they still cut just fine -- excellent finish, just takes horsepower and rigidity. Owners of small and light mills and lathes, this might not work so well...
 
It’s negative for sure. It’s a 1” 2 flute with a 3/4 shank. My mill has the power (2hp) but there may be some play in the head or pulley somewhere. It’s noisy when it cuts. Rattles. The finish isn’t bad, not spectacular. You can see where it rubs, however, I nodded the head last week and haven’t re-trammed yet. That would be causing something.
 
Those cutters work well in cast iron, the chip spalls off rather than curling.
 
Could I, or would I want to find inserts with back rake so it takes a bit less pressure to cut?
 
Could I, or would I want to find inserts with back rake so it takes a bit less pressure to cut?
Yes, as long as they fit snug in the mounting recess so it does not rattle around. You could also use cutters with a chip breaker, which would make them effectively positive rake, and would require less power, but would also be more fragile. Look carefully, what you have now may be rubbing on the clearance angle. Some cutters are designed for milling, others for external lathe use. That is all about relief angles, which are different for internal milling and external lathe cuts. A mill facing cut is effectively an internal operation. Working in a hole requires more clearance angle.
 
What I wonder about this cutter is what use it is intended for, the way the insert is presented to the work; it would not function as an end mill; I wonder if perhaps it is for CNC lathe work, turning and boring?
 
I was given this mill from a guy who probably recieved it free and likely doesn't know anything about it, frankly, nor do I.
 
The way the shank is built on your cutter, I believe that's to be used in a boring head, only. for cutting internal surfaces.
 
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