Accuracy of Indexed End Mill Diameters?

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SteveHGraham
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Accuracy of Indexed End Mill Diameters?

Post by SteveHGraham »

Here is a question that just occurred to me: will edge finders work with indexable tooling?

I got my first carbide-insert end mill a while back. Should I be able to take the nominal diameter as gospel? With an ordinary (new) end mill, you can pretty much assume the cutting will start exactly half a diameter from the axis of the spindle.
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earlgo
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Re: Accuracy of Indexed End Mill Diameters?

Post by earlgo »

When in doubt, run a test yourself. Set up the mill as you would expect to use it, use the edge finder, subtract the D/2 of the edge finder, add the D/2 of the mill and see if it hits or misses. Simple to do and note for the next time.
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SteveHGraham
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Re: Accuracy of Indexed End Mill Diameters?

Post by SteveHGraham »

Good idea, but will I have to do it again if I use different inserts?
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John Evans
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Re: Accuracy of Indexed End Mill Diameters?

Post by John Evans »

In theory no , that is why they are used in CNC machines. But, that depends on the tools and inserts quality. Cheap or worn tools and poor quality inserts will most likely not give consistent results. Home shop if tight tolerances check.
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SteveHGraham
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Re: Accuracy of Indexed End Mill Diameters?

Post by SteveHGraham »

It's funny that I never wondered about this before. I think of the indexable mill as a carbide fly cutter, so I haven't been thinking in terms of cuts that have to end at certain locations.
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earlgo
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Re: Accuracy of Indexed End Mill Diameters?

Post by earlgo »

SteveHGraham wrote:It's funny that I never wondered about this before. I think of the indexable mill as a carbide fly cutter, so I haven't been thinking in terms of cuts that have to end at certain locations.
This all depends on "How close is close enough?" but that is apparently a 2 pitcher conversation.

--earlgo
Before you do anything, you must do something else first. - Washington's principle.
johnfreese
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Re: Accuracy of Indexed End Mill Diameters?

Post by johnfreese »

The third character in the insert designation specifies the tolerance on the insert size. Cutter diameter can vary due to insert tolerance.
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